How do you like working out 5 days a week? Good that you have a solid friend who can help you.
Sounds like your diet is good, what about beef? What's your fat intake like, and from what sources (besides the fish)
If your diet is in check like you say, don't worry about supplements for now, you will still get great gains without wasting energy/money on them. Just need fish oil supplements, a good sport multivitamin, and whey protein. Since you are from Seattle area, I would suggest a Vitamin D supplement as I doubt you are getting enough from sunlight / food etc.
You are going to have to eat a LOT more than you are currently used to doing. To lose 20 lbs, you were at a deficit, most likely around 500 calories a day. So you now need to cover that 500, plus add 500 more... so an additional 1000 calories a day. About two more meals than you are eating, to make it simple I would just increase the portions in the meal pattern you are currently eating.
Maybe give some more details on your average day meal frequency wise, and what is in each meal, and what time you train etc.