If you are a newbie, i'd recommend starting with 1-2% per tournament, preferably sit and go's, they're much better for learning the mtt format. Once you feel confident you can step up.
Greetings, here in the forum we have a very good poker course, totally free, it will help you a lot to improve your game and the handling of your Bankroll
Here the link of the day 20 of the course, in handling your Banroll, Enjoy!