WordPress Permissions

I am having what seems to be cache issues with my wordpress theme.

The blog depending on traffic will take forever to load, if even load.

I have checked through the codex to try and verify what permissions need to be set, but can anyone give me a quick diagram of what directory needs which permission?

I have also tried installing WP-Super Cache but it doesn’t cache, even after reinstalling and following the troubleshooting steps. Is this a permission issue?

Thanks.