Im new at this but i want to learn how to make my car faster and stuff  

what car do you have?  

right now a 00 Camaro but im prolly gonna sell it for a 240sx or Eclipse (94-99)  

Me personally = not a big fan of domestics, but you'd probably be better off, power-wise, by throwing some bolt-ons on the SS...as opposed to trying to squeeze near 400hp out of a 240sx or an Eclipse.

Make sure you include some suspension mods on the SS, so you can take turns as well.

EDIT: My bad...I just looked back at your post, and you didn't say it was an SS.
So I assume it's probably a V6, in which case you should definitely upgrade to a 240 or anything with more than 100hp.
 

Whats the best website?? THIS ONE bwahahahah!! Actually, whatever car you have or whatever you want to get in the future, google it, and try to find a forum dedicated to that car... General boards like this one are good for general question but are not as specific about any single car, so that would be me best suggestion.

Also, what are you planning on doing with an eclipse or 240? Drift or grip, track, show, audio lol. What you wanna do?? Thats a big jump you stated, cause an eclipse is FF, versus the FR 240. Make up your mind, what kind of drivetrain you want then more options will open to you.. For example, if you are looking for a fun FR car, there are many choices depending on your budget: miata, 240, 300zx, supra, corolla 86 etc.. PS if you get a 2nd gen eclipse, dont get a 95. Those motors are the most prone to crankwalk for somereason..  

website??...just read magazines its always much easier, you get ideas from the featured cars plus it gives u info abotu the whole tuning business plus there are more than  enough advertisments for parts. Read superstreet/modified...theyre the best...and if u decide to get rid of your ponywagon cmaro and get soemthing *** "i meant japanese "i keep forgetting they edit the abreviated form pf japanese cuz it could be interpreted in a racil way" ( which a hiiiiiighly suggest, and if ur getting eclipse get GSX dont settle for GS or anything else) then you can start reading import tuner...but its kinda advanced i guess