I just bought to bonsai and I want to grow them, I need lots of information on how to simply. I have a japanese maple and a holly. One thing I can't find out is when its the 'growing season', is that just spring? Also when is a dormant period?I'm going to keep them outside, I read that you can plant them in the ground to fatten their trunks, should I do that? My maple is very thin and pictures I've seen of them are alot fatter.

Are you keeping the bonsai inside or outside? The maple should be dormant in winter. The holly grows year round. The maple would grow from spring through autumn.

I only know a bit about them. Some trees that are Bonsai material are of hardish wood. May be in families for many generations. This is not something to do without the training in a masters class for long sessions of hands on lessons. There are also Videos on the subject too but I don't have a set yet.Have you asked Google about the seasons of these Bonsai trees?