Piano

• An electronic keyboard is fine in place of a real piano, though of course a real piano is preferable (but I don't even have a real one! How sad!)
• Above all else, try to get a keyboard that has at least 76-keys (they generally come in three sizes: 61-key, 76-key, and 88-key.) 88-keys would be best, but can be too expensive depending on your budget.
• A built-in metronome would be very nice.
• Weighted, hammer-action keys. This ups the cost, but is very desirable in a keyboard. Try to get one like this if you can afford it.
• The number of sounds and techno-wizardry on the keyboard doesn't matter all that much. I teach my students how to play the piano, not how to play a synthesizer (two very different animals!). Just try to find one that doesn't sound intolerably fake with its piano sound.
• I have an Alesis QS 8.1, and I love it. They don't make it any more, but they do make a QS 8.2, and they managed to bring the price down significantly (from $1,500 to $800!). Unfortunately, the quality isn't as good, but it's not bad. Either way, you don't necessarily have to spend $800 to $1,500 to get a decent starting keyboard.