Screw down backerboard. It doesn't require so many expensive screws as advertised, but don't skimp at room entry points (doors), at uneven places in the floor and other places where skidding traffic might occur. Try to put whole pieces of backerboard in high-traffic areas and over spots that are uneven in the floor. Avoid placing backboard seams where tile seams are sure to fall (but don't go nuts trying to avoid it either).
The best mixing solution for thin-set is a large $10 plastic basin (black), a hoe and a round-shaped mixer mounted on a drill. Use the hoe to work in most of the water, then move to the drill and beater. Mix pretty thoroughly; you've got time. It should end up slightly wetter than brown sugar. If it's too wet, it won't bear up under the tile and you'll end up with an uneven surface.
Figure out, by trying with dry tile, where to start laying it. You don't want to cut too much tile, you don't want cut tile in high-traffic, high-visibility areas and you don't want the tile to look overly asymmetrical in the space it's covering. Consider, however, that you're going to have to measure and cut tile where you finish the job--meaning that despite your best calculations, you won't finish evenly, so don't assume whole tiles or specific size of cut tiles at the end of your job especially if you end at a wall or doorway where it's got to meet some limit. Do some research on the web here: I'm leaving you on your own beyond what I've already said.
Spread thin-set and drop tile. Don't press hard, but do seat the tile ensuring that a) grout lines remain exact and c) corners don't pitch up above surrounding tiles. Clean out thin-set from grout lines especially when higher than the tile's bottom: the grout needs room to bite. Use a tile spacer to rake the excess thin-set out. Use a spacer an inch away from each corner (when four tile corners meet, this means 4 spacers). To conserve spacers, remove and reuse them once you've dropped a couple of courses of tile since putting them down (the tile's not going anywhere).
Don't leave any thin-set on the surface of the tiles longer than a couple of minutes. It's hard to get off. If you have to remove some you missed, use a small, but very rigid putty knife to scrape it off later. Leave tile to cure for at least 24 hours (in summer, maybe longer in winter as a function of temperature). Throw the mixing basin away: you'll never get it clean enough for reuse.
Be sure to clean thin-set from hoe, mixing beater and float or you'll be throwing them away. Clean the first ones just after using them and before floating thin-set.
Preseal tile before grouting using sealant in a spray bottle. Do it once, rub in, wait 2 hours, then do it again and wait an hour or so before grouting.
The best mixing solution for grout is a 5-gallon bucket, plus the sealant (same as sealer step above, but in quantity to mix into grout in place of water), a round-shaped mixer mounted on a drill. Mix most of the estimated liquid in until homogenous, allow to sit 10-20 minutes, then mix adding the rest. The grout should be very thick, but not dry.
Press grout into grout lines in the tile using a mostly diagonal (to the grout lines) motion. Press hard. Keep the grout float at 45 degrees. Rake the grout back toward you to clean the tile.
Be sure to clean grout from mixing beater and grout float or you'll be throwing them away. Clean mixing beater before beginning to grout.
Wait 20-40 minutes to clean grout from tile and finish it to look nice in the grout lines. If your room is biggish, like a kitchen, then 20-40 minutes will mean not waiting after grouting, but going immediately to where you started and beginning to clean.
Throw grout bucket away when finished: you'll never get it clean without scratching the bucket making it useless.
Use many sponges. Soak them, but wring them mostly dry before using. Use a 5-gallon bucket changing the water very often to rise sponges. It's helpful to use 2 5-gallon buckets, filling one while rinsing in the other. Best is to have one person rinsing with one or two others cleaning. If you change the water often, you might be able to keep the buckets once finished.
Clean grout surface 3 times taking care not to touch grout lines with toes accidentally.
Cleaning the grout is easy because of pre-sealing! I just discovered this reading an oblique comment on the Internet after years of tiling. Especially for tile containing much relief (meaning with a rough surface), it's crucial, but even for cheap, "photographic" tiles it's well worth it in terms of the back-breaking work it will save.
If called for, caulk tile edges where good to do. Fill a small spray bottle with water and liquid dish soap (much more soap than would be used to clean dishes) to make the water slippery. Lay down a neat caulking bead, spray, then run finger over caulking line to remove excess which won't stick to wall or tile because of soapy water. Wait until caulking has set to wash off soapy residue.
After 3 days, seal the tile again using the spray bottle.