See CFTS, the Vancouver04 download, as well as some of the new stuff from Charlie just recently released.
What you try to do is develop your acceleration power and speed to 60, then develop speed endurance of that speed by work in the 80-120 range with limited recovery at ~95% effort as well as some special endurance 1 work in the 15-30 second range at ~90% with longer recovery (15-20 minutes). All of this, when combined with the speed in the 5-8 second range allows you to maintain your speed for a longer period. Weights and extended drive phase (keeping your head down for as long as you can accelerate without getting slower) also helps by helping you to save energy that you can use later in the race.
If your access to track facilities is limited in the winter you do the longer work as split runs (longer runs cut into shorter segments with short rest betweeen the segments).