Blizz,
I would recommend getting some experience washing houses and decks before you start bidding or even thinking about doing them yourself right now.
Do whatever you can to get some hands-on experience.
Phone all your relatives, and ask them if you can wash their house or decks for free. Then, you'll get an idea of how much time and materials cost to do various jobs. With that knowledge, just add in overhead costs, to figure your total cost to do a job, and the labor hours it takes.
For example, let's say your total cost to restore a deck is $200. It took you 4 hours, and let's say you need to make $75/hour. You would have to charge at least $500 to do the job.
Since I know what my total costs are for doing a particular job, I know what I have to bid to make the hourly rate I want. It's a number with which I can make a living. Your pricing will have to reflect your costs and the earnings you need to live on.
It will take you time to learn, you will make pricing mistakes, that's just the way it is for a time while you learn the ropes. Sometimes certain jobs are backloaded with challenging surprises that you didn't expect. It's common to underestimate the labor required to complete a job. After awhile, the more you do, the more you learn, it becomes easier to accurately estimate jobs.
I wish it was so easy to just plug in raw numbers all the time and make fistfuls of money.
Where are you in SW Mi?