Indeed, read the Harrington books (volume 3 as well, they're great to see whether or not you fully understand the tournament dynamics that are going on, especially late in the game). I had to read them 2 or 3 times each to learn 80-90% of the content, but it pays off.
When it comes to your question, it depends heavily off course on the situation (position, stack sizes of the other players, etc...), so giving a card range for these 9 situations is very rudimentary, but generally speaking:
- Early stages:
Are very similar to cash games, but you want to play a little more cautiously in general. Even if you have a pair of 10's pre-flop and your opponent goes all-in and you read him for AK or something like that (which technically gives you the best hand), don't get involved and put your whole stack at risk. You'll get chances to double up later and in better situations. Open with any hand you would open with in cash games when big or medium stacked.
*Big stack: Do not get involved in marginal situations that can cost you your big stack. Just play the hands normally as you would in cash games. In late position, I would play a little looser with potential big hands like 10-9 suited, after an initial raiser has been called by another player for instance. Be aware of the stack sizes though: do not give chips away needlessly when there's only a small amount to win. Implied odds are the key concept here. Attack weakness from the small stacks, but only if you think your reads are quite accurate. If you don't read very well, let this part go.
*Medium stack: Basically the same as above, but play a little bit tighter.
*Small stack: Play very tight and wait for a very good hand and good situation to double up. Stealing in late position might be appropriate if a couple of limpers are in the game and nobody raised, but only with an all-in move and a hand that is likely to be best at the table (e.g. a pair of 8's or AK). Fold equity must be high though, that means that you don't like big stacks among the limpers and your all-in must at least be a little harmfull if it would get called.
- Medium stages:
*Big stack: Same as above. Avoid confrontations with other big and to a lesser extent medium stacks and attack the small ones.
*Medium stack: Play a little more tightly when big stacks are in, but all in all same as above. Go all-in when you have a hand that's likely best and has some fold equity, but only if your reads of the table are decent enough.
*Small stack: Go all-in with any decent hand. This is paradoxically even more true in early position because you don't want your stack sliced by the blinds. A rule of thumb which I always remembered out of Harrington's book: going all in with T8o with 4 players to act behind you has EV+!
- Late (ITM/Final table):
*Big stack: Let the smaller stacks pick up fights against each other, but don't make the mistake of leaning back and let the others accumulate chips. You want to be more aggressive with your strong hands (which mostly means any decent hand with an ace, medium to high pairs, high suited connectors like even KJs,...), but don't put your big lead into jeopardy in marginal situatons when you meet resistance.
*Medium stack: Play tight (A7s+, A10+, 77+, KJs+, KQo, depending on position), but very aggressively. Stealing the blinds is a boost to your stack on it's own, so don't be sad to only win those with AA. Going all-in should be a little more frequent.
*Small stack: Very simple: All-in or fold. You may even lower your standards a bit in comparison with the medium stages because the fold equity is a lot higher in this stage, especially when there are no real big stacks. Yesterday, I reached the final table with only 2000 in chips and went all-in with every trash hand you could imagine. Not once was I called, and after 4 or 5 all-ins I pulled back to second stack, eventually winning the tournament. Read about first-in vigorish and the Structured Hand Analysis in Harrington vol. 2 to fully understand what is going on in this particular situation.
