I generally use the freeware (student) version of EAGLE, though there are some minor restrictions. It is user-friendly and makes everything look professional
I have also used ExpressPCB, though I definitely prefer EAGLE.
Here's a link--just click on "freeware" in the middle of the page.
If you are interested only in schematics, nothing else, you can download my PaintCAD files. I use M/S Paint, and copy/paste various shapes from the templates. Works for me.
If you think you may ever layout your own PCBs go with a PCB layout package as suggested by others. It will make the transition to PCB layout all that easier.
I usually do both. I draw the schematic with Paint as it is much neater overall, then draw it with PCB Express (the current PCB package I'm using), then use that for my netlist for the Sch Express. If I'm definitely making a PCB I refine the PCB layout with Paint and Gimp, making the pads fall within my personal standards.
Once you have a schematic drawn, even if it is by hand, it is easy to translate into another format such as a PCB layout package.
I cannot recommend any particular package, because I have only used Eagle since drawing by hand and using dry-transfer media. I have found that the ERC (electrical rules check) and DRC (design rules check) incorporated in Eagle and probably all purpose-designed schematic and PCB programs are quite useful and have saved me from making dumb mistakes. The ULP's and scripts for making changes are real time savers too.
The schematics made with PaintCAD by QuietMan that I have seen look very nice, particularly for publications and tutorials, and are better than Eagle for those purposes, I think. However, such general purpose programs don't have rules checks that I know of. I guess that is why he uses both depending on his needs.