A few things:
You could create a single SVN that can be used for all of your plugins, but then you will not be able to take advantage of the packaging system. In my personal opinion, this is the most attractive part of using the integrated SVN system, so I'd recommend against this.
Unfortunately, I can't help you out terribly with Tortoise SVN, but the basic steps are:
- Create your SVN through the web interface
- Copy the address, which should look like this: svn://svn.lotrointerface.com/TestProject-708
- Add /trunk to the end of that, making it svn://svn.lotrointerface.com/TestProject-708/trunk
- Using a guide check out a working copy of this directory to somewhere on your computer.
- Add the files, make any changes you want to make
- Then commit your changes using This guide.
Some notes:
- You can add the files to this repository keeping the exact same structure you already have, just drop them in the checked out folder and commit.
- You can make svn repositories for projects on lotrointerface.com that you don't actually publish, no worries there.
- This is how things are meant to work, just do what I've done above.
There isn't and won't be a 'magic' button. You commit changes to the repository using the guide I list above, and then they are pushed to the server. 'Reversing' that is a bit more difficult, since that doesn't really make sense in the context of development, but you can do everything you want to do.