E-How com on exterior painting looks like a great site for info and tips on doing the job right.
One word about their high pressure washer step in the process they advise. You might want to go easy on that, high enough pressure can literally wash away the actual wood. Don’t ask me how I know.
I like those washers, but the one my husband bought only lasted part of a season. He hasn’t gotten a new one yet (I’m bugging him on it) but is adamant that it won’t be a cheaper one, again. I sort of got addicted to the ease of washing off outside furniture and stuff with it. Although he was kind of mad at me for washing the deck and taking down the finish a bit. I didn’t know it could do that. Ok, so now you know part of the story, but I’m not sharing anymore information on that;)