How much maintenance is required with a bonsai tree?

I want to take up bonsai as a hobby, and I know that there is alot of maintenance involved.

Pruning of the branches, leaves, trunk and roots are essential. I don’t mind all this but would like to ask about the roots.

How often would I need to prune the roots/and or re-pot the tree? Does this vary for different types of bonsai species?

This website will give you some basic information on Bonsai Care http://www.bonsai-garden.com/

Additionally there are a series of bonsai related articles that address specific issues growers of bonsai deal with http://www.bonsai-garden.com/bonsai-articles.htm

Goodluck!