This is not required but If you want to use the perma-trails feature have search-friendly URLs mod_rewrite must be enabled.
We highly recommended nginx over apache if you are running MongoPress on a smaller VPS solution to achieve the best performance.
1) If you are using 64 bit os version, install mongodb 64bit version
2) Always check and update to the latest version of mongodb php driver -
http://pecl.php.net/package/mongo OR https://github.com/mongodb/mongo-php-driver
3) If in production, remove desktop environment (KDE,GNOME) and unused service. MongoDB need RAM.
4) Use Nginx, you will not notice the different when test on localhost/LAN but you will notice the improvement when run on production server.
5) Always using opcode compiler (eaccelerator, apc, xcache). We recommended eaccelerator because we have big success with them.