Well it'* all about how fast you want to go and what your willing to spend.
A basic tune up is a good place to start then..
If you just want to wake your car up then try:
A CAI or FWI (search)
A high flow cat
Try the 1.84 ratio from zzp:
You don't need to replace the valve springs and a similar raio has been proven to be the best for the L36. 1.9'* are too high. (www.easyperformance.com
look at ER rockers)
Just make sure you specify your a 95 L36 H-body car. the rear manifold differs in other years/bodystyles
And a chip can be done by gmtuners.com but I would highly suggest this for last. And you will also need a scantool and familiarality using it.
All that will really wake your car up but if you want to go farther then a cam and header install is in order.