If a creature can tap to do an ability, you can do that when blocking (for example, "Tap creature to do 1 damage"). But you don't have to. You do not tap to block. And you can't block with a tapped creature. Attacking Creatures are tapped unless otherwise noted (for example if the creature has the Vigilance ability, or it says "this creature does not tap when attacking" for older versions of cards). A creature does not need to have Haste either to block on its first turn out. I've been playing MTG since 1995 so if you have questions send me a PM.
EDIT: reading the official 166 page pdf of the rules, there is no mention of being required to tap when blocking. here's the link, its on page 53 http://www.wizards.com/magic/comprules/MagicCompRules_20090904.pdf