I use vsftp and it is documented fairly thoroughly. Check out their docs
. As for accessing your apache webroot, make sure that the user you are logging in as has read/write access to documents and make sure they are not chrooted. Or you could add a system user that has the webroot as their home directory and make them chrooted their. On most boxes the webroot for that user is in their ~/ directory so that they can be safely chrooted there.
I hope some of that helped.