Is there a minimum for that after-the-flop bet amount?

In limit play minimum and maximum bets are defined before you enter the game. For the first two rounds the minimum bet applies, and for the last two rounds you must bet the maximum (which is usually double the minimum). It doesn't matter what happened in the previous round.

In no limit the minimum bet is the big blind size, and again this resets for each betting round. The increment is then determined by the previous raise - if I bet $10 from left of the button and you wanted to raise, you would have to put in at least $20 (or go all in). You can bet more of course - there is no limit! Usually the minimum bet increases on the turn and river as with limit play, although I'm sure I've seen cases where this has not happened.

There are also spread limit games, which are like limit play but you can bet any amount between the minimum and maximum bets.

So talking of poker on TV - all the US coverage I've seen has been absolutely appalling compared to the UK's Late Night Poker (with Jesse May). Sadly LNP has been cancelled now, and replaced with Celibrity Poker Challenge which is rather less entertaining as the celebrities are usually crap at poker.

Rob

PS Roger - the empeg game is no limit but with no minimum bet, which does tend to mean we get too many people in each pot - but it's not like we take it very seriously!