that "brick heavy" feeling you get in your legs is probably pooling of lactic acid. aka, your legs are fatiguing. i usually get that feeling while i'm working my legs really hard, not afterwards....
anyways, heres what to do-
while not skiing, exercise your legs! do squats, leg extensions, leg press, calf raises, etc. also do some long distance biking (good because there is no impact like with running) or cross country skiing.... anything that gets your legs moving and burning. truthfully, skiing more is probably the best form of exercise to get your legs in shape for more skiing.
before and after skiing, STRETCH. this won't make you less sore, but it'll lessen the likelihood of injury (strains, pulled muscles, etc). also if you haven't heard of "the stick" you should look into getting one. they're used to roll out your muscles after exercise and the thing is absolutely amazing. makes your legs feel great.
the stick
last but not least, eat lots of protein. eggs, meat, peanut butter, protein shakes, however you want to get the protein into your system go get it. chocolate milk is practically nectar of the gods when it comes to protein content. not only does chocolate milk have protein in it, but it's also good tasting. studies have shown that chocolate milk does more for your body than a protein shake will.