I am going to briefly list my current home lab as well as some suggestions for those of you who wish to build a lab of your own. I will add this to my documents and update it as my lab grows. First, let me say this.. keep it simple.. It is easy to buy a lot of stuff that you do not need! Especially when you get into the habit of watching eBay for deals! For all of your associate level studies you will ONLY need three routers and three switches. I will focus on the CCNA R&S as well as the CCNA Security here as the topology will not change (nor hardware requirements). As you progress to the professional level certifications (CCNP/CCSP) you should only have to add to this existing lab not replace it.
First things first is the hardware. I personally like the 3640 series routers. They support tons of Network Modules (NM) and WAN Interface Cards (WICs). I personally own three of these routers. I would also recommend the 2950 Enhanced (EI) switches. I also own three. There are, however, other options available for your home Cisco lab. I will list some of these options below.
851W - This is a great choice if you want a wireless Cisco router that can deliver your wireless internet throughout the house. Another plus is that this is a k9 router that supports IPSec VPN. Perfect for your R&S/Sec studies. Regular 851 is the same without wireless. I would probably go with another model if you do not need the wireless.
871W - Ditto just more features and performance.
891 - Coming soon (Comparable to 18xx series routers) but would use in the stead of the 851/871 (Make sure to get 891W if you want wireless. I am waiting to buy one of these.
3620 - Avoid these if possible. Try to go with the 3640.
3640 - I love these routers.
3660 - These are nice as well but rather big and power hungry. I would still recommend the 3640 for home use.
26xx XM - The XM series routers are a perfect, albeit slightly more expensive than 3640, option for your lab. They are slightly more expensive than the 3640 and offer less slots. However, they do max out with more memory/flash than the 3640 which is nice when thinking about future-proofing your lab. If you find a good deal on these routers then they would be the better option. That said, the 3640 is usually much less expensive (Under $100 each) so this is still my recommendation.
18xx - These are great if you find a deal on one but otherwise I would wait for professional studies.
28xx - Ditto.
2950 (EI) - Perfect switch for your lab. Inexpensive and supports all CCNA commands.
3550 - These switches are nice and will be necessary for your professional level studies but not yet. Wait to buy these unless you find a crazy cheap deal on them as they will decline in price over time..
3560 - ditto (I am looking at buying a pair of 3550's and a pair of 3560's on down the line)
3750 - Wishful thinking.. These are expensive but support Stackwise as does the 3560's.. I will eventually buy one of these as well but they are not necessary for any of the Cisco certs...
2924 - These switches can be a great tool for playing around with CatOS as opposed to IOS. You will still see a lot of CatOS stuff in the real world and these switches are VERY cheap. That said, buy these AFTER you own some IOS switches if you want but not in the stead of.
ASA-5505 - You do not need an ASA or PIX for any of your associate level studies. I would wait until you reach that portion of your certification studies before purchasing as they will eventually drop in price. (Ditto 5510 etc)
I have owned several routers but have recently cut back to three 3640's as that was all I was using 98% of the time. I sold some and gave the rest away to friends. The reason I mention this is because it is easy to buy 8 or 10 2600 series routers that you do not need and will seldomly use. Remember that running 8 routers and 6 switches is steadily running up the electric bill.. LoL
I currently run this setup:
1x NM-1FE2W with 2x WIC-1T
Plus a bunch of ISDN and ATM modules that you do not need! (I just like to toy around)
3x 2950 switches (2x EI and 1x standard)
1x 2511 Access Server
1x Octal Cable
I also have three servers..
1x Dell PowerEdge 6650
1x Sun SunFire VT-100
1x Sun SunFire VT-120
I would recommend that you buy one server throughout your CCNA Security and CCSP studies. There is a lot that you can do with this. One obvious tool is http://freeradius.org/ If you download Ubuntu server edition for free you can install FreeRadius via the Synaptic Package Manager.. No need for the make/make install setup from the CLI. (Just for those unfamiliar with Linux). There is also a Windows FreeRadius option and students can purchase Windows Server 2003/2007 for app. $130! Ok.. Enough about that.
Now that we have covered hardware (and some non-Cisco software) let's move on to the Cisco IOS software that you will need on these routers. For your regular CCNA pretty much any IP Plus IOS will work. If you are going to contact your local Cisco SE and request an IOS for your router then it would be best if you get it right the first time. He/She may not help you out if you keep bugging them.. remember they are VERY busy people.
That said, roll over to the Cisco Feature Navigator and determine exactly what IOS you will be needing. http://www.cisco.com/go/fn If you are pursuing the Security after the R&S then you can go ahead and try to obtain this IOS release as it will support the features necessary for both!
ENTERPRISE/FW/IDS PLUS IPSEC 3DES
c3640-jk9o3s-mz.124-23.bin (This is no longer displaying in the FN so it could possibly be buggy.. You may want to go with 21a. Either way, look and study the available features. This is a great learning tool. Also, there is a compare link that will show you the EXACT differences between these IOS versions and their supported features. It's kinda cool!
THINGS TO CONSIDER:
You will probably want an access server of some sort.. IE. Cisco 2509, 2511, 2509RJ or 2511RJ. Or you can go with a regular 26xx series router such as the 2610 (or a 3640.. LoL) with an NM-16A or NM-32A network module which will allow you to use the same octal cables as the 2509/11. This will keep you from constantly plugging/unplugging into your routers/switches console cable every time you want to telnet in! Here is a nice simple config.. Just tweak it a little to adjust to your topology and paste it in to your access server!
You may also decide on down the line that you want to be able to access your lab remotely. That will work great if you have a nice VPN capable router delivering your home internet (such as the aforementioned 851W/871W or of course a 3640). But you will not want to leave all of your other equipment powered on all of the time. If this ends up being something that you are interested in then take a peek at a remote power controller. Here are a couple of examples.. http://www.remotepowerswitch.com/ and http://dataprobe.com/iboot-remote-reboot.html
Alternatively you can search eBay for 'SWITCHED PDU' to locate some nice rack mountable strips. These guys all allow you to log in via your web browser and an SSL HTTPS connection and remotely power your equipment on and off. If you go on a trip or to a friends/study group/user group/Cisco Live Convention etc. just leave your border router and remote power controller turned on and you should be good to go!
Regarding your electric bill you may want to call your local electric company and inquire about various residential plans. Some locations offer a steady MAX payment option that can be especially helpful if you are running a home lab. That said, with three routers and three switches (and using them as need.. IE. switches are off until working on switches etc.) you should not incur too much of an increase. I use mine about three times a week. Usually for an hour or two a night for two of those nights and a three to six hour stint on weekends.. My bill only jumped $30 (but that may not have all been the equipment).
I hope this helps!