I personally think business plans are a bit pointless in the general cleaning industry. ie pressure washing, carpet cleaning etc
its too unpredictable to forcast how many jobs you will do and at what price.
i mean window cleaning is simple, find out the average prices in your area , say £10 and work out how many monthly accounts you need to hit whatever target you need.
I mean you could do market reasearch and find out how much people pay on average per sqm say for jet washing but how can you predict how many jobs you will need in a month, some will be big some small and how can you forcast how much work you will pick up? 10k leaflets might be worth £500 or might be worth £5000 as you cant predict the responds rate or the job value form each person who responds. exactly the same with adwords etc.
To me to make any kind of plan for pressure washing is futile, same with carpets.
But the gear, do some reasearch, et some savings behind you and jump in and figure it out along the way.
personally unless you have a lot of financial backing i would say the best route in would be window cleaning, build up a 3 day a week round to provide you regular work, not only will you build contact with customers but then it give you a good base to push into other services somehwhat risk free.
this is pretty much what i am doing atm, currently looking at marketting and moving into carpet cleaning and driveway cleaning looking for the better paid work whilst a reliable window customer base
what ive said may be complete poope to you so goodluck