Daewoo Lanos Timing Bearing

Do i need to replace any bearing while replacing a timing belt?

Not unless your pulley is damaged.

I just changed the valves on a 1.5, as well as the timing belt.

First, if you're belt is still ok, set the timing to top dead center. If not go to the next step.

You need to take the timing cover off by taking the tire off, and then taking the eight or so machine screws off the cover. Set your timing to the right position (align top crank markings; align bottom for your pistons as well).

put your belt on, close the covers, put the tire back on. crank the engine and cross your fingers.

Do i need to replace any bearing while replacing a timing belt?

Not to contradict the last posting, but my pulley (the one on the right when facing the engine--not the tensioner) just cracked and fell apart. It seems they are plastic. The mechanic said it looked like the other one (the tensioner) was getting ready to go too. The belt itself did not actually break. It only got a gash in it when the pulley broke but the valves got bent anyway. My engine now has no compression. Two mechanics cannot figure out why. The first one gave up unless I wanted to get a new engine and the second mechanic says not to waste any more money on this car. I am hoping it may be saveable with the information from jwalker1970.
Anyway, I just wanted to caution you that the pulleys are not to be trusted and can cause as much damage to the vehicle as the belt breaking. My suggestion would be to have them replaced at the same time you change the belt. I've even heard that it would be wise to do this before reaching the 60,000 mile mark that Daewoo specifies.