From the trail head, go North on the Windsor Trail. Stay on the trail until you reach the top of the first mile-long climb. Here you will find the wooden fence marking the boundary to the wilderness area. Leave Windsor Trail and follow the fence line to the right (east) as it ascends Raven's Ridge, a gentle, broad ridge. Eventually the fence line ends, but continue up the ridge. Be sure to catch the incredible views of Nambe Basin, Santa Fe Baldy, and Lake Peak from the North Side of the Ridge as you ascend.
Eventually the ridge ends as it intersects a higher north-south ridge a little below the tree line. This higher ridge is the South Ridge of Lake Peak. Climb to the top of the higher ridge over easy scree slopes. The route is to your left.
As an alternative, you can access the South Ridge by hiking directly up the ski slopes of Santa Fe Ski Area, but the Ski Patrol might get on you for doing so. From the base of the ski area, ascend the ski slopes and stay to the left (as you face uphill) as much as you can. Eventually you wil reach a point where the trails begin turning to your right (south) and it becomes impossible to head north and east. At this point, leave the ski trails and head uphill (east). After a few hundred yards, you should reach the top of the South Ridge. From the top, simply turn left (north) and head toward the summit of Lake Peak. You will pass Raven's Ridge on your left a quarter mile or so after you emerge from the trees.
The route up the ski slopes is faster than Raven's Ridge proper, but is kind of a slog. In winter, this is the most dangerous part of the climb, what with all the crazed skiers zipping past you.
From the top of the South Ridge, head North along the crest of the ridge, which becomes narrower and more jagged as you get closer to the summit. You will encounter a few third class moves along the ridge. At one point, the ridge narrows to about 10 inches and becomes a little exposed. When there is ice and snow on the route, this portion can be a little tricky. After the narrow spot, the route becomes easier and eventually ends with the easy slopes to the summit.
When the route is dry and free of snow, no technical equipment is necessarry. When snow is present, however, ice axes and possibly crampons are recommended.
From the summit of Lake Peak, Penitente Peak (12,249') can be climbed by hiking east along the ridge that connects Lake Peak with Penitente Peak. Trail 251 links the two peaks together but, in winter time, only a snowy ridge is visible. The climb from Lake Peak to Penitente Peak takes between one and two hours, so be sure you have enough daylight left before committing yourself.
If you want to hike a big loop instead of reversing the route, don't turn around at the summit of Penitente Peak, but continue hiking northeast along Trail 251. As the trail descends from the summit of Penitente, it veers to the North and eventually intersects Trail 254. Take Trail 254 and head Northwest until the trail makes a sharp turn and begins heading Southwest.
If your feeling really strong, take a side trip up to Santa Fe Baldy by leaving 254 and following 251 to the Southeast ridge of Baldy.
If you elect not to do the Baldy side trip, follow Trail 254 to the South until it deposits you back at the trailhead for the Windsor Trail. This loop is between 12 and 14 miles long and makes for a long day. If you throw in the Baldy side trip, add a few miles and a few hours. To do all three, it is probably a good idea to camp somewhere along the way.