The National Trust for Historic Preservation previously posted some tips to tackle your historic house’s history. This was a great introduction into what kind of things you should look for to get started—tax records, Sanborn maps, deeds, and titles. Now they have followed that up with a Part 2, that has some more details and thoughts on research.
And one additional thought- please share with OregonHill.net what you have learned. I am happy to post it on here.