it's up to you and your personal interests. Good start is with an Intro level cert like CCENT, which is part of CCNA Routing and Switching. CCNA can be taken 2 ways: 2 exams or just 1 exam. CCNA taken 2 exam method includes CCENT (aka ICND1) and ICND2.
Cisco exams are a bit harder then ones from other companies (Comptia, MS, etc). if u haven't got any certs, look at CCENT as an intro to Cisco networking world providing fundamentals of networking (from Cisco perspective).
Even thou CCENT is not required to obtain other associate certs, it will be helpful in going thru Data center or other certs.
Note: 1st exam of 2 in Data center cert track is overlapping with CCENT; I call it mini-CCNA.
Whatever you will decide, browse thru study groups here and read "I passed" posts.
I would start with the CCNA R/S cert just to get the very basics of networking. Then if the DC curriculum matches up with your current job or a job that you want to get into then go CCNA DC -> CCNP DC. At some point you might want to look at the CCNP R/S track, too, because that's were a lot of this stuff starts to come together. What role do you currently fill in your Data Center-centric job?
My recommendation is: CCNA R&S is the base, for that reason, you must get this certification. After this, you can go for the Data Center track (CCNA DC and CCNP DC). Now, also you must learn about "Design" and "Project management" if you have these goals in your mind.
Always is better learn many things because you could work in many areas.
Thank you Martin. A co-worker suggested I start with CCNA Routing and Switching. I don't want to get lost in lingo and concepts Im not familiar with. It sounds like CCENT would be a good introduction.
I received from a co-worker the following course booklets, "Introduction to Networks", "routing and switching essentials", "scaling networks", and "connecting networks". Would these be appropriate course material for CCENT?
appropriate? Not really; they won't hurt but you should get and study from Cisco Press books. Cisco exams are unique and specific enough for dedicated publications such as books, tests, videos.
There are 2 series of books for RS CCNA: foundation library and official exam cert guide (OCG). most of us will skip foundation and get OCG as they look similar and cover same topics. (foundation library has not been updated recently)
In the past, however, Cisco recommended starting with Foundation first, then prep for exam with OCG especially if u do not have experience in networking. if u have taken Cisco class or other training (videos), or have experience, you can skip foundation library book. in either case, make sure you understand material and check exam syllabus before taking exam (use this site to check latest exam topics).
I recommend study with Mr. Odom's materials (and his web site), this site and forum, and anything else u can get. check out CCNA Routing and Switching 200-125 Official Cert Guide Library
Also, Get Packet tracer - a simulator from Cisco Net academy - which is a free now (after short registration)
Could not find recent Foundation CCENT book. Last one is from 2013; it might be still valid but be careful buying "old" books for exam.