Ferries in northern Europe

Haha, yes, that is true. The route is kind of in my head, but did not manage to get out in writing.
I’ll travel from southern Switzerland to North of Scotland, probably taking a ferry from Amsterdam to Newcastle. Over to Ireland, back through Scotland to Norway, zig zag through Scandinavia and Finland up North, stay in some places listed as Wwoofing (World Wide Opportunities on Organic Farms), find other jobs on the way and get new inspiration for the next steps in my life.
So, how could I get some infos on which are interesting routes, and maybe not the most expensive ones? I don’t need to rush.