I have just joined this forum and am very passionate about Bonsai trees.
If you do not have a bonsai tree, you first need to decide either on and indoor or outdoor bonsai. Then its a question of choosing one which would be ideal for new comers/beginners in Bonsai. As you have mentioned house plants, I am assuming that you are looking to acquire an indoor tree. I would suggest a ficus for your first indoor bonsai tree. You need to make sure that you find a good location where it gets plenty of light and air. You will need to water it, just like a house plant and in summer feed it with fertilizer such as grow-more. In the summer months you will need to prune the new growth other wise it will end up like a bush. Pruning the new growth is fairly simple task. Every two to three years it will need to be re-potted and the roots pruned by about a third. For the first re-pot, I would suggest that you take it to a local bonsai Nursery and they will do it for you for a small charge and you can see how its done and it you wish to do this your self in the future, then you will need to invest in a few beginners Bonsai tools.

I am a bonsai collector and grower and recently turned Bonsai Centre Retailer.
I am in the West London area and will be happy to help if you are within easy travelling distance. My site is: mikbonsai trees South West London | Unique bonsai trees for unique customers

I hope this information is helpfull.