"Network Admin" as in switches, routers, firewalls, etc.;
"Network Admin" as in the often used anachronism dating from the 80s for novell admins but actually referring to what's presently known as "Windows Admin," or generically "Server Admin"; or
"Network Admin" as in "Jack of all Trades IT guy" in smaller organizations?
If you meant the first one, which maybe you did given that you have a CCNA, then you don't need to learn Exchange and SQL server. It won't hurt, but it sure won't help as much as going for your CCNP will.
Also, consider this a branching-off point. It sounds like you might presently have a job in the "jack of all trades" category, which can give you a high-level perspective of many of the areas of specialization. Pick the one you like the most, and start learning your new specialty. Cross-training on the basics can be very valuable. Learning how to do basic scripting (perl, python, lua, whatever..) will save you much more time over the years than you spend learning it. If you encounter a repeatable process then automate it. If you don't know how, then learn how, and automate it. Sorry if I'm drifting away from your question, and into general advice for someone starting out. :-)
I also have to agree with some of the other posters, even if it seems like they're trolling. Get that A+ and Network+ crap off your resume! Nobody respects it, and it only serves to accentuate your inexperience. Start cramming and replace it with something better -- schedule your exam today if you need motivation to pick up the books!
Oh, and lastly.. Don't hang out posting on slashdot. Big waste of time!