I think it sometimes depends on the area you are looking for information in.
In general an encyclopedia helps you solve the search paradox (That is: You can't find anything unless you already know something about it).
* If you use it to find information about things you are already very familiar with, you'll be disappointed.
* If you use it directly as a source for things you are not familiar with, you will be mislead.
However, if you use your encyclopedia (Britannica , Wikipedia, Encarta) as a jumping off point to find search terms and sources, you'll find it to be most useful indeed.
In short, an encyclopedia is more like a richer dictionary, rather than a primary source of truth. (it isn't called a tertiary source for nothing!)
In general an encyclopedia helps you solve the search paradox (That is: You can't find anything unless you already know something about it).
* If you use it to find information about things you are already very familiar with, you'll be disappointed.
* If you use it directly as a source for things you are not familiar with, you will be mislead.
However, if you use your encyclopedia (Britannica , Wikipedia, Encarta) as a jumping off point to find search terms and sources, you'll find it to be most useful indeed.
In short, an encyclopedia is more like a richer dictionary, rather than a primary source of truth. (it isn't called a tertiary source for nothing!)