So, your muscles are sore after two days? This might be DOM. I would be sure to at least give your legs 5 days of rest before you train them again. You might want to consider increasing your reps. For example your routine might look like:
Squats - 6 sets
135lbs x 15, 155lbs x 12, 185lbs x 10, 205lbs x 8, 225lbs x 6, 225lbs x 5
Also, you can throw in some wide stance leg presses for 3 sets
Leg Presses - 3 x 10-15
Leg Extensions - 3 x 10-15
Lying Leg Curls - 3 x 10-15
Remember, the legs are very large muscles compared to the upper body. I firmly believe that high volume training is necessary to stimulate all of the muscle fibers. After a routine like this. . . your legs will be blitzed. This method has work for me. On leg day, I only perform 5 or 6 total exercises. . .then I'm out. Good luck!