power steering?

 

Liquid or spray stuff from autopartstore. Supposed to make old dry cracked belts OK again, but it's really only a temporary fix.

But now you say the belts are relatively new. New belts stretch a little the first week or so. Maybe they just need to be tightened? The reason they only squeal on startup is...
1 - They're cold.
2 - When starting the engine that's the one time the belt is suddenly started up. Puts a little more load on the belt vs. driving or revving the engine.

 

If they changed your belts recently, take it back to them, and tell em one of them is loose. They should be able to tighten it up a little, and take care of the problem. Dont let them just spray belt dressing on it as that is just a very temporary fix.