Low level Jungling is fairly difficult. The small advantages from having Runes and Masteries really add up in the Jungle. When I was low level, I simply could not Jungle with most Junglers aside from Warwick and Nunu. At level 30 without Jungle Specific Runes, Lee Sin's Jungle for me is fairly difficult.
I would just get Runes that are useful for a wide range of characters first and worry about serious Jungling when you are 30. Fiddlesticks is an excellent Jungler and uses basic AP runes if you want a good Jungler now. For now, I would just stick with Laning as Lee Sin.
Cheers.