Great advice from the other ladies, just wanted to add my bit -
Totally agree with the 'no emergency formula' bit, too easy to give in at 2am etc etc...
Even with a great latch it's not ALWAYS a great latch, and even one feed with a not so good latch (that you don't notice at the time) can have painful consequences, you just need to push past it if you can.
Regardless of how many people ask if you are SURE you have enough milk because bub is feeding constantly/you can't seem to express much/the moon is in Virgo/whatever reason - as long as there are lots of wet nappies and bub is gaining weight, you are doing a great job. People try to be helpful and often just make you doubt yourself.
Being used as a dummy is great for establishing supply... and it can be hard at first to figure out what is productive sucking and what is comfort sucking, so I figure stay away from dummies for at least 6 weeks or so.
The amount you can express has little to do with how much your baby can get out, they are FAR more efficient.
I found Lansinoh stained my clothes.
Make every effort to have bub with you in recovery, ideally skin-to-skin and on the breast, even if not actually feeding (though that's ideal).
I've read that the more sucking and skin-to-skin contact, the faster your milk will come in... My DS was on the breast almost constantly (he wouldn't sleep for longer than 20mins anywhere else) since birth (by CS) and my milk came in on day 3 I think...
Consider safe co-sleeping if possible (once off the heavy pain meds) - great for milk establishment.

Oh and the most important thing - take your time, relax and enjoy this new person you've created!