Also is there any advice on how to view a 'straight' or a 'flush' as your first two cards (is this called in the hole?). At the moment I'm working along the lines of playing either of them as long as the pot will comprise at least five times what I have to put in, otherwise fold. I haven't yet got a post flop strategy, but you'll see that at the Rawk tourney......
Generally if you're dealt two connecting cards, it is a good idea to just let them go. 87 offsuit for example. You can be dealt 'suited connectors', which as the name suggests would be 87 suited. This can be worth holding onto until the flop. With this hand your strategy should be to see a flop as cheaply as possible. Chances are you won't hit a straight or flush on the flop, but the turn or the river might make it for you.
You're along the right lines of working out what you have to put in to the pot to play, and what you'd be winning (this is called the pot odds). If theres 200 in the pot and it costs 50 to call, you're getting 4-1 on the pot. Whether its a good idea to call or not depends on the odds of hitting your card.
For a flush draw (that'd be, say, 2 clubs in your hand and another 2 on the table), the odds of hitting another club are about 5-1 on either card, but as there are two more to come, its 2.5-1 over the rest of the hand (52 cards in a deck, 13 of which are clubs. You know there are already 4 of them out, which leaves 9, and the deck has 47 cards left in it that are random. 47/9 is 5.2, rounded roughly to 5-1). Bear in mind that it might cost you some more to play after the turn. But this is variable, and also where position comes in. Say you have position against one more hand. You're holding two clubs, and the flop lands seemingly random cards, say 10c 8c 3d. The other card makes a stab at the pot, say betting 250 to make the pot 500. You're getting 2-1, and I'd say its worth playing. After all, theres a good chance this bloke is bluffing with those cards. If you stick around, it isn't stupid to imagine he will just check after the turn, and regardless of what lands you can then decide whether or not to make a play at the pot yourself. Position is all important here.
The same goes for hitting a straight, but again just beware how many outs you have. If its an open ended straight draw (you have 8 7 6 5 and need a 9 or a 4 to take the pot. That gives 8 outs, roughly 6-1 or 3-1 over the turn and flop) you have a much better chance than an inside straight draw (you have 9 7 6 5, you need an 8. 4 outs, 13-1 or 6.1-1 over the turn and flop).
It is a little bit of mental arithmatic, but well worth doing. It becomes second nature after a while. You get used to what you need to call a draw to a straight or flush. What I find it does better than anything is gives me an excuse to play the cards I have. If you're in position and someone checks to you, its almost a semi bluff to make a bet of about half the pot.
I was once told that you don't win poker by the hands you win, but by the ones you fold. It takes as much bottle to let go of a good hand as it does to bet big with a marginal one trying to steal the pot. I've been dealt QQ before, put in a good size raise early position, and then seen three players after me go all in when they had no reason to (big stacks, low Ms). Some people would be rubbing their hands together thinking of quadrupling the size of their stack. After a good think, I let it go. One of the three players turned over KK, and he still lost the pot to a flush!
One more bit of advice: buy the first two volumes of Dan Harringtons series 'Harrington on Hold'Em'. I can't sing the praises of these books enough, he can explain this shit better than I ever could, and you can believe him cos he's won millions at the World Series of Poker a couple of times...
Where as I won $30 a few times on Bet365. Bit of a difference...