Mohair, first off you really want to restore the rear shifting. The three steps at the front are much too coarsely spaced with much too large jumps to use for daily riding.

As mentioned it's highly likely that the system is just gunked up. Flush out the front shifter with some mineral spirits (AKA "low odor paint thinner) and clean or replace the cable and housing for the rear shifter. That is likely all it needs.

You'll also gain a lot of speed and ease of riding by replacing your old dirt knobbies with smooth mountain bike sized road tires. Two that I've used and highly recomend are Ritchey Tom Slick and Tioga City Slicker in the 1.5 inch width size. Either of these options will make your bike ride really nicely.

Being as the bike is an old '92 model it's an iron clad certainty that all the bearings in the wheels, headset and bottom bracket will need cleaning and re-greasing at this point. There's also a very good chance that the spokes could use some attention to bump up the tension closer to optimum and true the wheels to serve reliably in this new "born again" riding career.

Be wary of getting too wide and cushy a saddle. When you set up the saddle height to the correct placement where your leg is almost straight at the bottom of the pedal stroke the back of your thigh tends to push your butt forward and off the wide spot of such saddles. You end up riding on the nose of the saddle and THAT is not comfy at all. Either that or you are constantly pushing yourself back only to end up again forward and on the nose. This is why folks that ride a lot tend to move towards the narrow and nasty looking saddles. Besides, part of riding for fitness is working out on the bike. And riders that are riding that seriously don't sit on the saddle so much as they use it as a place to position there body with much or most of the load always being carried by the feel on the pedals. It's only on the "sit up and beg" beach cruiser bikes that the riders can actually USE those big wide saddles. But that's only because they don't set the saddles up to the "proper" position as they are not in a big hurry to get anywhere. Does that make some sense about why saddles tend to be narrow and uncomfy looking?

If you're interested in doing a lot of the maintanence work on your bike yourself check out the descriptive how to's at www.parktool.com/repair .