I think a general idea of pot odds
is required at lower stakes. This is because many players at these levels will pay you off which allows you to make bets that at first calculation appear unprofitable but won't be due to the opponents you're playing against.
I've printed off a huge bundle of basics and little extras it includes:
How to play specific hands: AA, AK, from the SB, low-mid pairs, JJ, KK, QQ and something I need to play more to be less nitty suited connectors.
Raising draws for value
Free card myth
value betting the river
I realise that I won't be applying many of these concepts (mainly bluffing) and I'm in danger of overplaying cards at low stakes against people who won't realise the sublties but I still want to learn and move up so I'm building the foundations now.