As a long-time Mac user, I'm always looking for good advice on maintaining my Mac, especially freeing up disk space. I found this post from "Baby Boomer" on the Apple Mac discussion forum.
Empty the trash
Open up your application folder & go through all your apps. Trash all the apps you no longer want and/or use. An easier way to do this is to open the Application folder in list view & press the Command+j keys.
In the the dialog that appears, click the "This Window Only" button & the "Calculate All Sizes" check box. Wait a bit until your file & folder sizes have all been calculated, then click the "Size" column to sort your apps from the fattest to the most anorexic.
Get rid of all your photo files you don't want and/or need. Same goes for those pics off the websites you downloaded (gifs, jpegs, etc.).
Get rid of all your music files you no longer listen too. Especially, if you already have the actual CDs and/or DVDs or you can later redownload from a website. Use Spotlight to make sure you got rid of everything. You can even trash directly from Spotlight!
Drag what you don't want and/or need to the trash. Better yet, download this neat little shareware app demo called AppZapper. It basically does all the work for you by not only trashing the apps but the apps preference files, caches & all its associated files. Another software that does the above is AppDelete. Best of all this software is free! Burn what you want and/or need onto CDs or DVDs.
Not everyone has the luxury of purchasing an external HD and/or a .Mac account to store their "stuff, junk, music & photos". You can check with your ISP to see if they offer free storage space. Most if not all do now-a-days. I store all 5000+ of my music (mp3s) files & 500+ music videos in my ISP storage bin. There are thousands if not millions of free storage facilities on the web also. Use your favorite search engine, Google &/or MacGoogle to search them out as they come in different storage sizes to fit your needs & wants.
Check for duplicate fonts. Applications>Font Book. Select “All Fonts.” If you see any “black dots” next to any fonts this mean you have duplicates and/or multiple versions of these fonts. To clean this up, select a “black dotted” font or the Apple + click to select multiple dotted fonts; Edit>Resolve>Duplicates. What this does is turns off the duplicates & multiple version fonts. Not delete them. More than likely the “extras” were installed by other programs and/or other users. Clear out font caches Use FontNuke. It does all the work for you. And, best of all it’s FREE.
Printer Drivers:Get rid of all the printer drivers you don’t need & use except the ones for your current printer(s)/scanner(s). HD>Library>Printers Folder. If you accidently threw something out that you needed for your printer/scanner it can be easily obtained from the manufacturer’s website and/or from the CD that came w/the printer/scanner.
Garage Band has about 1GB of loops stored. Get rid of some some them. You surely don’t use, like and/or need them all. HD>Library>Audio/Apple Loops>Apple>Apple Loops For GarageBand. Or just get rid of the Garage Band app altogether if you don’t use it.
Get rid of extra languages. Strip your computer down to your “native” tongue. You can do this with a FREE utility called Monolingual. Another app that apparently does all the work for you. I’ve never used it. However, a lot of users here swear by & recommend it highly. However, there is a warning for native English speakers. Make sure you keep BOTH English and English (United States)..
Other Resources: Knowledge Base Article http://docs.info.apple.com/article.html?artnum=303602 Mac Maintenance Quick Assist. Scroll down to "4) Prune Through Your Files".Slimming your hard drive.
Rule of thumb: You should never let your hard drive get to where you have only 10-15% of space left.