In SharePoint 2007 (MOSS 2007)
1. Go to the site where your library resides.
2. Click Site Actions>View All Site Settings 3. Click the Document Library that you want to delete. Once on the AllItems.aspx page of the library, select Document Library Settings from Settings Menu.
4. Under Permission and Management, click Delete this document library. 5. Once you click Delete this document library link, a confirmation will be poped up informing you that all the contents of this library will be deleted and sent to Recycle Bin of the site (depending on your deletion policy).
6. Press OK to delete the library.
In SharePoint 2010
1. Open SharePoint site on which your document library resides which you want to delete.
2. Click Site Actions> View All Site Contents menu.
3. Click the Document Library that you want to delete.
4. On the Library Tools tab, click Library.
5. On the Library tab under the Settings group, click Library Settings.
6. Click Delete this document library on the Document Library Settings page under Permissions and Management.
7. Click OK to confirm your action.