Assuming you are laying laminate wood flooring that is pre glued. Whether they have a real wood veneer or everything about them is fabricated, you should allow the boards to sit inside your home for at least two days to fully acclimate to your home's conditions before installation. Failure to do this can cause rippling or gaps between the boards that can be impossible to fix without tearing the planks out and starting from the beginning.
If there is some type of existing floor it needs to be completely removed before laying the first piece of your new laminate. If you are replacing an old floor, cut it into manageable pieces and pry them up with a long handled scraper for best results. Make sure every piece is up and then vacuum. Make the floor as even you can you without sanding. The most important thing to check for and fix are low spots, if you let them go you will have a squeaky floor.
After that you put down the underlayment. Start from the walls and work out from there, use a utility knife to cut the underlayment to fit the room. It's not a bad idea to mark up the underlayment to use as a guide when laying your laminate boards. Use a wood spacer to leave an expansion gap between your laminate and the wall, then work your way out from there.
You should have to only moisten the glue on the edge of each board for it to activate. Then slide the next board into pace and press it firmly against the previous for a good, snug fit. You want to use a pry bar to protect your wall once you start laying the last of the boards. Simply ease the end boards into place and you're done.