Gonna do a good tune-up on the '91 Maxima tomorrow, but I have neither the owner's manual or a service manual. What kind of fluids am I looking for, and what amounts?

Motor OilCoolantTransmission Fluid

Also, any suggestions on brake pads\rotors, and tires of the standard size? (P215/60/R15, I think)

The VG30E holds 4 1/8 quarts motor oil with filter.

The transmission takes 7 7/8 quarts Dexron II-E. Power steering also uses Dexron II-E.

Coolant capacity (total) is 8 3/4 quarts

OEM tire size for your Maxima is 205/65/15. There are so many viable options in that size range, and they're so cheap that it's worth getting good ones.

I believe stock brake pads are ceramic (they are for my 93 at any rate). So if you have OEM rotors, the best option for pads is OEM or as-OEM ceramics--anythign else can damage the OEM rotors. If you're replacing rotors and pads, get whatever combo you like.

I don't know if yours has rear drums or rear discs. Mine's got drums. I just go with re-surfaced shoes from autozone/kragen/whatever. They're drums--shoes are pretty much shoes.

I saw that you mentined doing plugs/wires/rotor in another thread. Do NOT let the store convince you that Denso are OEM equipment for the Maxima (as autozone tried to convince me). Only put NGKs in it--just like with the Q. Make sure you pick up some anti-sieze compound and electrical contact grease--any decent shop will give you some with your plugs and wires. Gap plugs to 1.0-1.1 mm, and torque to between 14 and 22 ft-lb