[PantsOnFire]

I have memorized all preflop heads up odds in general. You should know things like pair vs. pair, overcards vs. underpair, etc.

As for outs when the flop comes, you should learn to calculate. The easist way is to simply double your outs to give yourself a rough percentage. For example, if you have a flush draw you have nine outs. Thus, you have about 18% to hit your flush on the next card and about 36% to hit it in two cards. You can get slightly more accurate by dividing the number of outs into the number of unseen cards.

So here is how I do it as an example. I have seen a flop and a turn. I have two pairs and I know somehow that my opponent has made a straight. I have four outs and there are 46 unseen cards. So I roughly have an 8% chance (2 x four) or 11:1 (46:4) odds of making my full house on the river.

"Calculating pot odds seems quite difficult if say the pot is paying us 111 and the bet is 106."

When you cacluate pot odds, like calculating draw odds, you can round off to simplify. So your example is easy in that you need to put in 106 into a pot of 217 (111+106). Exactly 2:1 would be a pot of 212 (106+106) so you are getting very slightly better than 2:1 odds. You don't need to be exact to make your decisions.