If you're looking for a film camera to be used to learn photography, feel safe with any of the leading Japanese brands-Canon, Nikon, Pentax, Olympus and Minolta. They are built to last and they perform flawlessly even with age. The most common ones are those silver top cameras with black leather on the body. It would be best if the lightmeter was working and the batteries are still available.
If you want to go cheaper, look at the European brands like Praktica and Zenit. The cheapest ones are those that do not have lightmeters. If they have lightmeters, most wouldn't be accurate after all these years. You can still buy them with a lightmeter just don't depend on their readings.
Many good samples can still be found at eBay but if you want brand new, go to B&H. As much as possible, avoid those late model film SLRs that resemble dSLRs. They have AF and modes that will veer you away from learning the basics although you can still use them at full manual mode.
Now you know!