For the past few days, when I started my jeep it would squeal for 10-30 seconds and I thought it was because of the cold. This morning I went to start it and it cranked and wouldn't start. I tried again and it just clicked. Tried to jump it for at least 30 minutes and battery seems fine, but still won't start. Not sure if the squealing has anything to do with it, but would really appreciate some feedback. Spark plugs and coil pack recently replaced....could it be the starter or alternator?

 

The squealing is most likely a loose serpentine belt or one of the components it drives has failed (or is failing). How did you check the battery? You said "battery seems fine" look here for battery testing:
http://www.2carpros.com/articles/how...-a-car-battery

When and if you get it fully charged many auto parts stores will do a load test to confirm the battery's health.

So, tighthen your belt and test your battery. Check the water level in the battery too, if it's low only fill with distilled water!