On the web you can use trac to work with svn. But that assumes svn works. Why doesnt svn work? I'll assume you dont have apache access. Regardless I suggest using git or mercurial (both work on linux and windows). Distributed source control is much superior.
I use gitolite to set up repositories on a server for ppl to push to. You only need regular shell access. However i only configured it using the superuser method. If its just you and your team you can simply use ssh instead of gitolite. If you know nothing about git i suggest watching this fairly entertaining video
If your problem is because you don't have shell access i suggest getting a VPS (virtual private server, its essentially a shared dedicated server with each share inside its own VM). i use linode but was happy with vpslink as well. (I only tried two)
You wanted webbased. Gitolite uses a different method. You can create/remove repositories but pulling the config files from the server onto your machine, modifying it, commit and push it back on. On the push some triggers/scripts will occur making the changes you want. However if its just one team you could just use ssh. I use tortoisegit
Theres a learning curve to git (configuration and using it) but the video above helps you understand how it works and then using tortoisegit will be less strange.
First i suggest going to github.com creating an account and public repository and try getting toutiousegit working with that.
For shell access log into your shell and write mkdir mytest; cd mytest; You either need to write git init --bare here if you have git installed or do it on your local computer (right click a folder and use git bash) and copy the folder onto the server using something like winscp. Create a folder on your comp with the any name right click and create a git repostory. Using what you learned from github (or online manuals/tutorials) add files to git and commit it.
Now pushing it is updating you remote copy. You should have a bare repo for each user, if its complicated you may consider using Gitolite (which installing may be difficult if you dont know what your doing). You can pull your teammates bare repos and thats how merges are done (bonus marks if you create multiple users and setup linux to have read access on all the directories and write only in your own.). Anyways to push it to the server (or pull) you need remote locations. Go into the settings with tortoisegit then go under git->remote on the left pane (its near the bottom).
Remote: MyRepo, Url: shelluser@site_or_ip.net:TheFolderYouCreatedWithGitBareRepository putty key you can ignore. You should now be able to push and each time it will ask you for your shell password. If you dont want to enter your password create a private key with puttygen and go back to the git remote settings and add your private key. Then add your public key to ssh authorization keys.
From this site
Copy your local public key to the remote server
If your remote server doesn't have a file called ~/.ssh/authorized_keys (note it said authorized_keys2 but i am sure its a typo) then we can create it. If that file already exists, you need to append to it instead of overwriting it, which the command below would do:
scp ~/.ssh/id_rsa.pub remote.server.com:.ssh/authorized_keys
