For CDs I use Audiograbber -
http://www.audiograbber.org/ - and rip to MP3. MP3 being the most portable format - that is you can play it on most anything, including Ipods. Windows Media will try to rip to WMA, and Itunes defaults to ACC, which not all players will play.
Make sure when you load the CD you click the FreeDB button or it's equivalent. Then the software will look on the Internet to identify the CD and fills in the metadata - the names of the songs, album, and artist. You can set the format you want this in too - use something like "Track#-TrackName-ArtistName." Looks at the Options to define the directory structure - I use MP3/Artist/Album. Depending on your processor it should just take a few minutes per CD. Stack em up and pop them in and out over a weekend as you're passing by the PC.
Note programs like Itunes will maintain a "music library" for you but I prefer to do that manually. This makes it easier if you need to free up space on a hard drive later and can just move a portion of your MP3s to an external drive.
Cassettes and LPs are a lot trickier. You need to get either a dedicated cassette or LP player player with a USB output, or get an RCA to USB cable and then run it from the player into the soundcard and record the song in real time, and then fill in all the metadata manually. Here's a primer:
http://www.wikihow.com/Transfer-Cassette-Tape-to-Computer