First, if you are worried about performance at all, use Nginx + uWSGI. Cherokee is essentially abandoned.
The two areas of caching that might be helpful are 1) static assets like images and 2) database queries. For static assets, I suggest using the free CDN, Cloudflare. For database queries, use Web2py's caching feature: http://web2py.com/books/default/chapter/29/6#Caching-selects
