I've decided to write a timeline on this topic for three reasons. First, I have always thought that Vikings were awesome.
Second, the topic of Viking/Norse what-ifs has not been touched upon that much on this website, as far as I can ascertain.
Third, this topic lets me pick a starting date of exactly 1000 AD, which is cool.
Basically, the Vikings led by Leif Ericsson found colonies in Markland (Labrador) and Vinland (Newfoundland) that are successful.
For now I have to go, but tomorrow I will start the TL. For now, post any comments/ideas/suggestions that you have.