According to a recent literature review of studies on alcohol and it's impact on sleep, alcohol will definitely not help a person sleep better. While people who drink may fall asleep faster and deeply at first, they are more likely to have greater disrupted sleep as the night's sleep continues. This means more tossing and turning, and less restful nights of sleep.
So for those that think drinking will help them get to sleep-- well they are right. It will help them hit the pillow faster. However, the studies show that the night's sleep will be anything but restful once the 2nd half of sleep sets in. This reduces REM sleep significantly, particularly for those who have had moderate to heavy amounts to drink, and leaves a person feeling much less rested than a person who did not drink or drank very little.
Instead of using alcohol to help with sleep or to just get a better night's sleep when it counts the most (hello, finals) try doing some other sleep better techniques. Here are a some suggestions to get you started: Ten Ways to Sleep Better.
If you choose to drink this weekend, try stopping at buzzed to reduce the negative effects alcohol can have on your sleep. The more you talk to others ,dance with friends, and sip mindfully means the more restful sleep you'll have, and the more productive day you can enjoy in the morning.