New players

[Raowulf]

In pro games and tourneys, deck building is essentially the crux of the game. In more friendly environments, it's not so important as having fun is. If you're happy with what you've got then don't worry, you can always jig them around a bit later on.
As Etched says, 60 is the minimum, and in a tourney it'd need to be 60 to stand a chance cos you'd need to know there was a higher chance of that 1 card that'll win you the game coming out but in a friendly you get to practice more with what you've got and to be honest, I've played friendlies at my last club against tourney style decks and its no fun to just sit there whilst your opponent lays 10 cards on the table in turn 2 and removes all 20 lives off you. But hey, that's the idea of a tournament.
I'll happily play a friendly against anyone anytime. I think I know the rules enough to teach them.