Department stores tend to run a little pricey but have a big variety of choices. Some department stores have a clearance rack with dresses up to 50 percent off. Look also on the clearance racks for some great savings.
Discount stores have a variety of choices and have name- brand items on sale.
Your favorite regular retail store or stores where you buy your regular clothes that you know have a special occasion or more dressier section of clothes are usually to your taste.
Bridal stores. If money is not an issue, bridal stores have a great selection of dresses specifically for homecoming. The staff is usually friendly in helping you one on one to pick out a dress.
If you already have a dress style in mind, great. Having a style in mind, you can limit your choices making the choice easier. If you don't want to pick a style just yet, an easier way to decide is get a bunch of different dresses to try on and see what looks best on you for your body shape.
Trying on dress is very important. It might look good on the rack or online, but until you try on the dress you'll never know. The color, cut or even length might look great on someone else, but not on you.
An easy way to start is to pick the color you want your dress to be and search for dresses of that color. This makes your choices fewer so it is easier to pick your favorite. Also keep in mind your favorite color may not be the color that looks best with your skin tone, hair, eyes etc.
Shopping online can be tricky if you are last-minute shopping. Dresses can't be shipped in very quickly. This is good if you have planned ahead because you can always return it and pick another one (shipping time in mind) if you don't like it.
However, shopping online gives you a good idea of what kind of dresses there are in one page. And if one just screams to you to get it and you really think it will look good, it's a perfect opportunity to get it. Online shopping will also up your chances of someone else not having your dress.