Ceritification Differences

I just signed up for the A+ HW & OS exams. When I signed up, I noticed there were tests ranging from 301, 302 and 601 up to 604. My vouchers are for 301 & 302. Does anyone know the differences in these exams? I was under the assumption that the A+ exam was only one exam.
Comments
Are those VUE or prometric vouchers? Call them to see if you can use it for 2006 objectives instead, maybe you would choose to write the newer objectives if you could use it for that.
new (2006): http://certification.comptia.org/a/default.aspx
update information: http://certification.comptia.org/a/New_A_Calendar.aspx
A+ resources (both 2003 & 2006): http://certification.comptia.org/resources/find_materials.aspx
No, the vouchers are only good for those two exams only. Had I known prior to taking the A+ class w/2003 information that a new class was out already, I would have chosen the newer information of course. This was not information the school gave any of us prior to signing up for the class.
I do plan on taking CCNA coming up in July. Any advise for preparing for that exam?
As for CCNA, this exam is so widely talked about, both online and offline, in digital, printed, and verbal form that you could probably read and read until the cows come home.
For now and until you've passed at least 1 of the 2 A+ exams, I wouldnt recommend even touching any CCNA materials, if and when you're ready for something in the Cisco world, I'm sure others here will start to tag their comments to any of your posts. For future reference, here's something to start with:
http://www.techexams.net/forums/viewtopic.php?t=7268
http://forums.cisco.com/eforum/servlet/PrepCenter?page=main
Wish me luck.
don't forget to come back and let us know the news.