How do you level in oblivion

In order to increase your level in The Elder Scrolls IV: Oblivion, you need to improve your Major and Minor Skills in any combination a total of 10 times (i.e. if your Major Skills include Athletics, Blade and Heavy Armor, you can improve your Athletics 4 times, Heavy armor 5 times and Blade once). After performing these, you will receive a message stating that you need to go rest.

To level up in Elder Scrolls IV Oblivion you need to try pacticing using spells. When you've leveled up in a spell on the top left hand corner it'll say (spell type) go rest and meditate on what you have learned. Once it says that, find a place to sleep at an inn or at your house. When you sleep, a thing will pop up and say you've gained a level. Choose three atributes you want to level up, and then press B on your controller. You can level up constantly and go all the way up to level one hundred or more!

If you are playing on the PC version, you could press the tilde key (~), then type in 'advlevel', then press enter.