Translation instructions
TortoiseSVN is still in development so the translation of all resources is also a work 'in progress'.
General
The TortoiseSVN project uses gettext PO (portable object) files for its translation. PO files are plain text, so you can even translate using a normal text editor. The only thing you have to take care of is that the editor can handle the UTF-8 charset. There is a wide range of tools out there that can handle and manipulate PO files.
How to translate
Visit transifex.com and register an account there. After having done this, go to the TortoiseSVN translation project and request to join a language team of your choice.
Transifex has a nice web interface. You can edit everything there, but you can also download the .po file, work offline using your preferred editor and upload the .po file to transifex again.
We take care of synchronizing the translations between transifex.com and our repository.