Painting - Front Porch & Rear Deck

Front Porch & Rear Deck installed in July 2001. Most of it is pressure treated, although the colonial posts are not. We have never painted or treated it in any way. We want to apply a white colored stain to all. There are no visable stains.
What is the proceedure for staining?
Do we need to pressure wash the wood? Do we need to clean with a fancy wood cleaner at the harware store? Do we need to sand the wood? In what order?
Thanks in advance for your suggestions.

Power washing wouldn't hurt...but clean it must be...but first, a sanding with 40 or 50 grit paper would benefit you and the bite/snag that the wood would give to the applied stain. 'Fancy' cleaners can be good too. Mill glaze can be a problem but sanding will open the grain so the stian will adhere. I'd make sure the deck has grayed enough in the weather, as it sounds it might have by now, before sanding, then cleaning...one good coat of white should do, but two thinner coats over a couple of days is just as good, if not better. May I ask how close to grade your deck is?

Porch is 2' from grade, deck is 10' from grade.
Thanks for the suggestions.

You're welcome, sounds like you'll be just fine. Have fun with your project Ron.

Clean with an oxygenated cleaner. Do not use bleach. Read the labels!!! Most deck cleaners contain bleach.

Power washing CAN hurt!! Most h/o have the pressure too high which removes some of the wood, create splinters, and do other damage. If you power wash, set the pressure to a low setting. With no visible stains and only a year old, you probably don't need to power wash.

About power washing!! I did it, didn't know about what pressure to use, and , as another person stated, caused it to splinter. My daughter got splinters in her feet from it. Resanded those areas. I applied stain after 6 months. In florida with the heat, I am going to stain each year. Note: Tried polyurathane once on a deck, it peeled all over the place. made a mess. Eventually replaced the plyurathane areas.