You've been given some good advice, but I wanted to add a word about paying off a mortgage early. It may not be the best thing to do investment wise, but as one who chose to pay her mortgage off about ten years early, I can only say that the emotional satisfaction of knowing that you will always have a roof over your head is well worth any possible missed investment returns. I had to talk my husband into it, but he has thanked me time and time again. We live in a very low tax area so we won't have any problems paying our taxes despite now living on retirement savings and SS. I know too many people that are in their 50s and 60s that still have many years left on their mortgages, including one of my own sisters. I enjoy the security we have without a mortgage to worry about.
That's definitely something I've considered and that's important to me.
Right now I'm working towards building what The Intelligent Asset Allocator called a 'Portfolio Policy', although the book never mentions doing things like working a mortgage into the policy. But essentially I want to determine how much risk I want to take on, and get an idea of our retirement income given a number of scenarios.
The good news is that right now I'm a part of the Ontario healthcare pension, which is an incredibly strong pension. If I theoretically finish my career with my current employer I'll be getting monthly payments to the tune of 3k/month, in addition to the Canadian Pension Plan and any savings. So prospects are already looking pretty good, but I'm well aware that a lot can happen over the course of (now) 28 years and so I need contingency planning.
I'm also leery about what you mentioned in another post, that with the way the U.S. is going right now stocks may not be the wisest decision. All of these books talk about 'risk', and yet I wonder what the 'risk' is when mathematically we're supposedly going to see perpetual growth over the long-term.