First of all sry for my English.
I know this is a little guide but there is no guide for S3 so i did my work here. :D

Always start Jungleing at blue! Ask your teammates to do some damage on Blue buff so you can stay over the half of your hp! Then go to wolves. Then you can already try to gank mid! If you stay in Jungle kill the red buff, but only if you got your smite back! After that it is easy to jungle with olaf. The only thing which is important, start attacking blue buff with your Q, but throw it as short as you can so you get your cd lower.

Start gank always with Q to slow your enemys and attack with E to do some true damage on them.