I used to Regedit most of my Windows customizations. But now, the TweakIU program provides a GUI for many common changes. Here are some of my favorites:
Read the "tips." There will be some handy keyboard shortcuts. (Did you know you can hold down Control to select many taskbar items? Also, when confirming file actions, Shift+No will mean "No to All."
Under Internet Explorer, you can set the loading-page animation, which I used to great effect. (When I use IE, now I have a running Mario icon when a page loads). I also changed a registry setting so that "Internet Explorer, brought to you by Mario" is in the title of each window.
Finally, under Templates you can edit the entries in the Windows "New file" menu. (This is under the file extension in HKEY_CLASSES_ROOT). I added a "Rich Text Document RTF" entry by pointing to a new .rtf file on my hard drive. Wordpad can be a good lightweight editor if you want simple formatted text. (And, you can use Paste Special/Unformatted to strip formatting). So I always associate .rtf files with Wordpad.
No, rtfm is not a manual in rtf format. It means something else.