I am putting up a new site. On the home page I want to put a summary of my main sections on the site. These sections will also appear in my Nav bar. Will having 2 links on the home page pointing to inner pages be a problem with SEO?
Depends on how many links the page has. Two links to one location on the same page is not that big a deal. Too many links from a single page can be. Wiki can serve as an excellent tutorial in effective on-site linkage. One of the reasons they rank so high for virtually everything. Huge amounts of contextual on-site links (and off-site links in footnotes and nofollowed).
I think it is a normal practice. Usually we would use a top navigation bar and a left catalog for navigation purposes.
stuff your title tag with keywords and watch google list it all go works. This is my typical practice and it works great.
no it will not. lot of people use a top nav bar in image or flash format and use the bottom/footer navigation for text linking to inner page. pretty common practice