The long story at WP “Using Subversion” is not for everyone, at least not for Windows user with limited Linux knowledge.
So how do you actually put your plugin on WordPress and make it searchable and updatable via self-hosted WordPress dahsboard?
Let me put it this way.
1. You need to have a repository account. Apply here.
2. Download and install Tortoise SVN.
3. Create a SVN folder in your PC (any names). Right click and SVN Checkout. You will get 3 directories trunk, tags, and branches.
4. Fill trunk with your plugin files, make sure readme.txt comply with requirement. Use validator here.
5. Right click on trunk and Commit. Make sure all the files checked on the prompted windows.
6. Right click on trunk again, pick TortoiseSVN/Branch/Tag. Replace trunk with tags/1.0 (or your stable version in readme.txt)
7. Right click on tags and SVN Update
For more details and graphical view, visit this entry.