We have a plumbing problem with our shower faucets- how can we fix them?

Our house was built in 1968 and our most recent remodel was a few years ago. We retiled our shower ( professionally ) and also had them install new faucets. Since then we have started having problems and it has progressively gotten worse. The cold water faucet seems fine ( hard to tell because we have a water saver showerhead ) but the hot water is barely turned on to get a warm shower. It's almost off- when you turn if off, it doesn't even seem like you are actually turning it, it's so slight. My husband said he has the parts to fix it, but he hates plumbing, and dreads taking it apart, that he won't be able to fix it and it'll only be worse, or create more problems. Anyone know what might be going on with the faucets? I don't know the brand-so we couldn't contact the manufacturer- but I would hope it's a good brand because we picked high grade tile. Also, the cold water faucet drips when we are showering- not alot but enough if you happen to get underneath it! The hot water in the rest of the house is normal.