Find a list of screenshots of common dialogs here.
The context menu is the main way of interacting with TortoiseGit. In the following image you see several possible options. The options shown are tailored to the current context (e.g., "Add" is only visible for unversioned files and "Diff" is not visible here is only shown for modified files) - you won't see any commands that you can't use in your situation. There are also enhanced drag'n'drop context menus.
Tailored context menu for (ignored) .patch files:
Drag'n'drop context menu:
Support spell checking (English + different languages based on installed language packs), basic styling and, autocompletion of filenames as well as method and variable names for various programming languages
TortoiseGitMerge can open Git patch file directly, you review it and patch to working copy.