what do i need?

we better let jeff answer this,no matter what we tell ya,he will put in his 2 cent,s worth of BS.

It kind of depends how far you wanna go. If you wanna keep it (relatively) simple you can do a cold air intake and get an exhaust kit. Those are both things that you can do fairly easily with basic tools. If you wanna do a bit more you can always look into a turbo or something but if you have a 3.8 you might need to do more work because from what I was able to find when researching for my '96 the 3.8 used in the Mustang has too high of a compression to use a turbo. Thats probably enough to get you started unless your looking for some serious mods.

If you're talking power adders, turbos will add the most power but as said it will require a lot of work (and money). You'll need stronger engine parts (heads, cams, etc.) to handle the compression. My '96 V6 was supercharged and didn't need anything extra--stock parts were fine. I'd suggest this route. Depending on your year, there are many kits out there, but I recommend either Vortech's S-trim, which is what I had, or ProCharger. If your working with a "student" budget, then exhaust, cold air intake, and other bolt-ons will give you some good power. Look into underdrive pulleys, headers, and a bigger throttle body. If you can handle those bolt-ons AND a power adder, you got yourself quite a machine in an underrated package.