CircuitMaker Student Edition
CircuitMaker 6 Student Edition is a free download, although it is no longer supported by the original developer. It still works fine under Windows XP.
Here is a zipped file that contains the program and installer: Click here to download the ZIP file (5.67 MB)
There is good on-line help in the student edition, but it often refers to the User Manual. If you really want to read further, here is the user-manual; it is a zipped PDF file: Click here to download the instruction manual (1.49 MB)