JP,
> I intend to hang some drapes against the wall and use some bookcases as basstraps <
That's really not going to cut it. Drapes absorb only the highest frequencies, and bookcases are, well, let's just say they're not useful as bass traps. This is not to discourage you! But there's no sense wasting time and effort on things that won't work well either.
> Please keep in mind that my budget is very reduced <
Complete DIY info for all of this is in my Acoustics FAQ:
www.ethanwiner.com/acoustics.html
--Ethan