It might surprise you to know that the main purpose of a bookcase is to hold books. I am just teasing a little bit here, but there is a wider variety of bookcases than you might imagine. You can find a simple bookcase, one with doors, one with drawers, or one with an attached desk. This variety is styles is great if you know what you want but can be confusing if you are just beginning to search.
Bookcases with Doors
There are a few reasons that you might be interested in bookcases with doors. If you have books or knick-knacks that you want to protect from dust and humidity using a bookcase that has doors will do that. The doors are normally glass, which makes sense; because you will want to be able to locate a book quickly, you want or look at your collectables that you have displayed in them. To make it more complicated you can get several different types of doors. The first type has doors that open from one side to the other. This is the most common type of bookcase that you will run across. If you want to get fancy, you need to look into a barrister bookcase. These have doors on each shelf that opens up. Do not get your hopes up though because they are hard to find and expensive. I totally forgot about the ones with the solid doors that go across shelves. This is where people hide their ratty paperback books. I know this because I have sneaked a look into them on occasion.
Bookcases with Drawers
A great space saving piece of furniture is a bookcase with drawers. These drawers are normally on the bottom with shelves on the top. If you have some books or things you want to display but not enough to fill an entire bookcase try finding one of these things with drawers. The drawers can be useful for holding whatever you do not want visitors to see while your pretties are still out for the world to admire. I find this style to be one of the most versatile and attractive of the styles that I have seen. Even the newly made ones have a nice look to them, just because they are not that common. At least I have not seen all that many, but I do not get out all that much. The drawers do not have to be one the bottom but most that I have seen have them there.
Bookcases with Desks
In modern times, having a bookcase / desk combination is the way to go. It might surprise some of the younger people but this is not a new invention. A great little bookcase desk combo is called a secretary bookcase. This is a letter writing desk with a fold up surface. You certainly could not put a computer on one but you can use it to hold mail or whatever. It does not have to be useful because it is so cute. Most people, when talking about a bookcase with a desk, mean a computer desk. These are readily available and come in many different styles. Most of these seem to have a hutch with shelves over the desk. These work great but you can find some creative combinations. You can find everything with an entertainment center type deal attached to a desk or a huge swath of bookcases. I wish you luck on this search because the choices are dizzying.