Boiling a lobster is the simplest way to cook lobster and leaves you with the purest taste of the lobster meat. This is how I first started cooking lobster, and I'd say it's the quickest way to cook a lot of them if you're cooking a few at a time.
Be careful the water doesn't boil over, as it may froth up over time.
If you're cooking more than one, you'll need to play with the times a bit. Suggested cooking times for a single lobster:
|Lobster Size||Boiling Times|
If you've overcooked the lobster, the claw meat will stick to the claws when you're trying to get the meat out.
Lobster Anywhere has a decent guide on cooking times.