A friend of mine just found 3 rolls of exposed 135 (i.e. 35mm) film. They are at least 10 years old. He'd like to know if it is even worth taking them to the local hour photo lab but also if he should give them any special instructions.
I don't know from experience, but I think it would be possible for the film base to deteriorate after such an extended time, and thus cause it to become more fragile. I would consider developing it by hand rather than having it run through a machine which might put undue pressure on the roll. Also - In my opinion, "trying" it is always worth it ;) You never know what you could get!
If these films are B&W, then I would advice to process them in an highly diluted developer with a 'normal' contrast working, such as the good old RODINAL (still made by ADOX in Germany). I would dilute it at 1:100, with a pinch of Borax added, in stead of the traditional 1:50 or 1:25 dilution. Of corse then the developing times will be (very) long but there will be some compensating effect (the negative will have to be printed on a higher contrast grade, but I would prefer this way than a contrasty developer). And, more important, the evolution of this slower process can easily be monitored with an IR viewer. This is what I do when developing 'rediscovered' films containing important information.
If no IR equipment is at hand, developing by temporary inspection in a very dim green safelight at a distance of at least 1,5m and for a short time, might do, but only after about half the estimated developing time. Wet and (partially) developed film tends to lose some of its sensibility for light, but only very slightly!
Be aware that over dated, exposed and then long time 'forgotten' film tends to lose its effective exposure and contrast, has enlarged grain, dull shadows and bleed highlights. Printing it will be not that easy...
For colour film, there is no way around the standard processing, wether it be C-41 or E-6.
If there is any chance that the images are worth saving, I would not take it to a one-hour photo lab. I'd find a local commercial film lab, and have them do the processing. You never know what the state of chemicals are in the local one-hour lab, and since film is no longer mass market, I'd be very concerned that they even know how to do film anymore.