I\'ve decided that modifying files directly in notepad is probably dangerous and it was about time to have some proper source control (I am quite new to source control). I have
An even simpler way than Robert's Answer (although lifting from it):
Open the repository browser of TortoiseSVN and create a new directory for the project you want to check-in.
Check-out this newly created empty directory from SVN as the directory you are wanting to add (ignore the warning about checking out into a non-empty directory).
Execute 'SVN Commit...' on the directory you are wanting to commit, selecting the files you want to add from the commit window.