Because it's not always in the same easily-identifiable spot, your best bet is to:
1. Consult your owner's manual: This is the most reliable source. The manual will have diagrams showing the location of all fluid reservoirs.
2. Look for a small, plastic reservoir with markings indicating "Power Steering Fluid" or a similar designation. It might have a dipstick or markings on the side to show the fluid level.
3. Search online: A quick image search for "1995 Oldsmobile Delta 88 power steering reservoir" might show you pictures of the reservoir's location on similar models.
Remember to be careful when checking or adding power steering fluid. The fluid is under pressure, so be aware of potential spills.