Here is a small collection of schematic symbols originally by Tim Williams that you can use to make your own professional looking schematics.
The set has been added to over the years by many contributors, including Dennis Dunn and yours truly, as well as a couple of anonymous parties. Thank you to all!
What they are is a set of symbols in bitmap format. Just copy/paste the symbols into your favorite image manipulator (even M$ Paint) to draw up your own schematics.
Circuit_Symbols.zip - 50,342 bytes (revision 10/20/2009)