Welcome to the forum, WW. I recently "graduated to this forum myself, after building a couple of systems.
You will definately enjoy building your own system, and it can be done on a budget. The advantage of building one is the upgrade capabilities, which are limited on a Dell or other proprietary system.
Couple of random thoughts:
Do you live in the city, with several outlets to shop from, or you gonna mail order everything?
The Asus A7N8 deluxe is a good board, might find it bundled with a processor if you shop around.
One stick of 512 DDR ram is sufficient, buying more will not noticably increase perfomance.
Choosing a case is a matter of personal preference, but the Power supply is extremely important. Bundled power supplys will "max out" if you plan on adding several drives, or high powered vid cards, etc.
IMO The best all around price/perforamnce ratio for cpu/ram would be the AMD 2500+, and PC 2700 DDR.
If you are ordering online, check the DOCS DEALS thread for specials on components. Very Helpful.
I also like to read the pruchaser reviews at Newegg of a part I am considering. Tells you the real deal from people who actually bought it.
Hope this helps..
Just one more thing
Be careful, or you might
end up with this