Did it two years ago aboard a rebuilt CAL-46 (Cal-Vader 49).
Best time to go is in the fall (we left late September and it was pushing it). This is due to the North Pacific High. I will let some more experianced members chime in, but basically the high moves around and its calm in the middle. The winds rotate in a clockwise (i believe its clockwise...) motion around this high. When you leave Hawaii, you will be sailing North until you catch those winds, then basically slingshot East toward California. Only thing...the high moves around. *grins*
We were at sea 23 days...but it was a bad October weather-wise. I live in Hawaii and alot of friends said that the trades weren't strong at all and it was very humid while I was gone.
I hope this helps! Oh, any port is good...generally the more northern ones (we went into Monterey Bay) will save a few days off the voyage.
PS...let me know if you need crew. I live on Oahu and am looking for a boat back to the mainland this summer.