I started using Parchment paper, it's found with the wax paper at the market, you just can't see through it as well but nothing sticks to it. I also use the plastic wrap as Tom mentioned. Never tried homasote but it looks pretty good.I have been using the same old soft pine building board I made several decades ago but it has been added to over the years as required.
Plans can be cut to fit the board or folded. Anyway you can do it. If you want to make a copy of the plans Kinko's does a nice job. Sometimes I do and sometimes I don't, depends on my mood and the plane I'm building.