Clean the play head with some isopropanol alcohol and a Q-Tip first. It will dissolve the iron oxide that builds up on the head.
You will need a 1/8th inch stereo cable, both sides male.
Find a loud part of the tape. Turn the volume down to zero, and then press play. Do a sample recording and bring the audio up to where it is almost about to clip.
There are a number of recorders of OS X.
Here is a
GIANT list of them
If you don't want to read the list provided above, then here are some options.
Audacity is my favorite (as far as freeware goes), but it is slow. It's benefits are that it is cross platform ,and there are lots of plug-ins available. It even supports a limited form of NYQUIST plug-ins. If you have a text-editor you can write NYQUIST plug-ins. It can decode MP3s and many other audio formats. The only way it, and many other applications can encode into MP3 format is by using a
LAME encoder (More
LAME encoders. The reason for this cost, decoding the format is set, and free. The primary encoders are all pricey, with licences starting at 30k (if I remember correctly). You can also find OrgVorb and other encoders that will plug into A
udacity via the Library folder. Audacity is also opensource.
Similar to Windows audio recorder is Audio Recorder.app Simple and free.
WireTap is a routing and recording program similar to Audio Hijack. You can rip and record from streams, DVDs, speakers, jacks, and the microphone. Both are good programs, and the limited version of WireTap is free.
If you have specific questions about any of the Mac audio apps, post them, and I am sure you will find at least one user.
I work as an audio-monkey(enginer), using mostly PC and software at work and my Mac at home.
Note: Some of this post is recycled text