When getting ready to build a new site or redesign a site one of the most important tings you can do is plan out the website architecture. How many folders do you need and what should you call them? How many files are you going to keep in the root folder? Once you know the answers to these the rest should come quite easily.
You see when you have applied this thought process to designing your site it becomes much easier to plan the rest of your SEO for the pages that make up your site. Take a piece of paper or open a text editor and actually lay out your site prior to building it, be sure to use the file names you want for each page as well as the names for your folders. When done, sit back and take a look at the structure and fine tune it if needs be.
Start with your main index file and work your way down from there. For instance your document might look like this;
It does take a bit of time and effort to create a site tree but once it is finished I am sure you will be referring to it regularly when developing your search engine optimization campaign.