OK, so now that you've gone and worked your way through day one, it's time to tackle Day Two.
Cleaning up the spaces you can see. This is quite a hard part for me and my partner as we tend to stash things everything. We get home from work and shopping and we put things down wherever they happen to fall. Sadly, they tend to stay there. That is the hard part. Cleaning up what can be seen and organizing the spots so when you come back to them later, you can easily find the things you need.
For me, this means having to clean up every day, or every few days as we go about our business around our home. Sometimes it means whenever I leave the room, I carry something with me to put it away in it's rightful place. Other times, it means taking 10 minutes and cleaning up the clutter and the haphazardly thrown items just so we can have some living space.
Of course, don't be afraid to toss the things that are clutter. You can organize clutter all you want, but in the end, you'll still have a pile of clutter. Just a nice looking pile of clutter.