Can you rent it? If so, how much is it usually? I'm going on a skiing trip with my friend in late January and my family is low on money, so I'm trying to earn the money to make it work. Also, what other gear do I need (hats, gloves, etc)? I'm not sure where we're going for it.
Certainly you can rent it. If you are low on cash, it is probably the best way to go. Rentals will vary depending on the resort. It could be as low as around $20 per day per person for skis, poles, and boots. If you were to buy these things new, expect to pay $500+ for the set...at the low end ($300 for skis, $200 for boots, and $50 for poles). Of course you could always buy used, and get the skis for $100, boots for $75 and poles for $25, but this still means $200 out of pocket. If you don't plan to ski more that 6 to 10 times, it isn't worth buying the equipment. Call whichever resort you plan to go to and ask them what their rental prices are. If you are going to an expensive resort (which is sounds like you probably aren't) buying the used equipment may actually turn out to be your cheapest option if you are going to ski for 5 days and rentals are $50 or more per person per day. You just have to do a little research.
As for other gear, yeah, gloves (WARM GLOVES...not knitted ones) are a must. And I would seriously consider a helmet. They are usually offered as rentals for under $10, but prices may vary. The advantage of a helmet is that it not only protects you, but it is VERY warm. Even in the coldest climates, you'll love having it. As for clothes, jeans and the likes aren't you best bet. Even with long johns. They get wet easily, and consequently get you cold quickly. A ski bib is probably best, but a snow suit will do nicely. Of course a warm coat. Goggles are awfully handy on snowy/windy days. Not mandatory, but helpful.
Where are you planning on going for your vacation? And about what time? If you are going in the spring, some of the "warm" stuff won't matter so much...
I drink, therefore I am!
Putterman's answer was excellent, as always. Let me just add that some resorts have sporting goods stores a short drive away that will offer rentals for cheaper than what you can find at the resort itself. So once you decide where you're going, hit google maps to see what's near there, or along the route that you're driving anyway.
Another thing to consider is lessons. They can be expensive, but they're absolutely worth it.