1. Sort out plumbing and electrics first making sure that you've got the sockets in the right place. Install the electrics but leave the plumbing/drainage at this stage. The two other posters give excellent advice on this. If you have a gas heater/boiler in the kitchen turn this off and cover it up if you are going to need to do any major amount of drilling in its' vicinity, such as core drilling an outside wall for an extractor duct. Gas boilers really don't like dust! If your boiler hasn't been stopped and started in a long time it may be worthwhile getting it serviced so that it will fire-up again after the kitchen installation (I've had one or two which refused to do so - not nice!) Similarly smoke detectors need to be protected from excessive dust (a disposable latex glove works well if looking slightly weird)
2. Walls. If they aren't plumb then this is the time to sort them out by reskimming or dot and dabbing. They don't need to be perfect, but somewhere near plumb/straight does help! It is also a good time to install plywood pattresses onto weak stud walls if you have to use them to support upper cabinets
3. Install the extraction ventilation (as this may require core-drilling of the wall). Run any plumbing or drainage which requires clipping to the wall at this stage and box in this and any exposed extraction ductwork, etc where it would otherwise be an eyesore.
4. Painting. As others say expect to touch-up afterwards. I prefer to get this done prior to installing any flooring to reduce the possibility of spotting, etc
5. Flooring. I prefer to fit this before installing the units if tiled, but I generally install timber/laminate/vinyl flooring afterwards to minimise the risk of damage to the surfaces. Remember to make provision for the difference in height between the old floor and the new if you are doing this or you'll struggle to get appliances like washing machines, etc in place
6. Install lower cabinets
7. Install worktops, install and plumb-in sinks, etc also gas hobs, etc. Worktops should protected with cardboard or plastic sheeting whilst the installation is completed
8. Install laminate/stainless steel backsplashes (as required)
9. Install upper units, extractor hobs, connect ventilation duct, etc
10. Tile splashbacks (as required)
11. Detail units (cornices, light pelmets, plinth boards, etc) and drawers, shelves, etc.
12. Install built-in appliances
13. Clean-out insides of cabinets. Fit drawer fronts, doors, etc
14. Caulk-in and seal worktops, etc
15. Snag the completed kitchen
This works for me with my tool kit and seems to avoid any process potentially cause any damage to a previously installed component. If in doubt always cover completed surfaces with some form of protection if it is in any danger of being left exposed for a while - I do a fair bit of commercial work and a major bugbear is going back to something only to find that it hasn't been protected and has been damaged by another trade - less likely in a domestic kitchen I agree, but nevertheless worth thinking about.
