transfer old audio cassettes to my mac desktop

I have a dozen audio cassettes from 1978-1985 that i would like to transfer to cd or file format to preserve the voices.

My desktop mac is two years old and runs os x 10.9.5.

What is the easiest way to do this?

i read that if my mac has a 3.5 mm line-level input that i could connect a cassette play directly to my mac.

Does my mac have it?

what is the easiest way to transfer the audio cassettes? do i want then in wave format?