Ace to five triple draw plays exactly like deuce to seven triple draw expect that hands are ranked differently. Just as in Deuce to Seven, you are trying to make a low hand but unlike in Deuce to Seven, in Ace to Five straights and flushes do not count against you and Aces play for low. This means that the best possible hand you can have is A2345 with flushes being irrelevant to the rank of the hand. In Ace to Five, A2345 is called a wheel. A2346 is the next best hand and is called Number 2 or a 6-4. The next best hand is A2356 and so on. 23456 is the worst possible 6-low and the fact that it is a straight does not count against you.
Other than the ranking of the hands, the game play is identical to deuce to seven so please refer to the game rules for deuce to seven to understand the how betting and drawing works in this game.