UPDATE: Forget everything in this article -> Just go get Git for Windows v1
Install msysGit http://code.google.com/p/msysgit/Create a SSH key using Bash (id_rsa and id_rsa.pub)Install TortoiseSVNUse plink
Use puttyGEN, which comes with TortoiseGit, to create a Putty private key from id_rsa like so:
puttyGen –>
Conversions –>
Import Key –>
Open %userprofile%\.ssh\id_rsa –>
Save Private Key as private.ppk (or whatever you want)Register your Public Key (id_rsa.pub) with GitHub i.e. Copy/paste the text inside the file into your Github account SSH Key (https://github.com/account –> SSH Public Keys)
Set your details from the Git Bash command line. The token is available from your Github Account Settings.
git config –global user.name “Your Name”
git config –global user.email “your@email.com”
git config –global github.user your-github-name
git config –global github.token your-github-token
Get the Repository’s Read + Write SSH URL

Clone the repository to a folder using TortoiseGit
Load the putty key %userprofile%\.ssh\private.ppk if that is where you saved it.
Disclaimer
This is a rough summary of what to do, and more of a reminder to my future self. If you have any suggestions, let me know.
Quick correction, that should be “register your *Public* Key (id_rsa.pub) with GitHub”. The private key should stay on your computer.
Good catch. I have updated it.