With Tortoise, it's as simple as opening the folder in explorer, right click -> "SVN Update", write code, make sure it doesn't break anything, and when you're done go to the same folder in explorer (optionally selecting only certain files) and right click -> "SVN Commit". I do this all the time from my work machine (where I could only install the express edition to dabble in some projects during lunch) and it has yet to break anything on the IDE-integrated side on my home system. Under the hood, SVN doesn't know you're talking to it through any particular medium. IDE plugin, shell plugin, command line...no difference.
Edit: needed to mention - all my comments deal specifically with SVN as your source control. There are other tools as well, most notably Git and Hg.