SubVersion help and scripting.

I have a (Gentoo + webmin) dedicated server on which I installed SubVersion. I need a very efficient way to create new repositories on it, grant access to users, and have them update a website from the repository if needed. Doing so by email would be great. I have created a basic Bash script to do such functions so you may start from that. I'll have questions on what is feasible and what is not, if I should use the command line or which tools I should use, etc. This is therefore a job to exchange with an SVN expert to communicate with me and advise me on tools, and who maybe will have to improve or create a small script. Thank you.