For detailed instructions, see the corresponding areas of the THL Help section.
The Drepung Monastery website has at present three major sections - Home, Colleges, Spaces, and Essays. Each of these has diverse content, and can be accessed by clicking on the corresponding tab on the top horizontal menu bar. Once you click on a given tab, you will first be presented with a "home" page for that section, which provides short blurbs to various components along with thumbnail photos. In addition, there is a right hand side vertical menu which is specific to each section. Thus, when you choose "Spaces", the right hand side menu will change and offer options specific to Spaces. The only comprehensive index to the specific content for a specific section of the website if offered in these section-specific right hand side menus.
The main resource within the Drepung Monastery website is essays. An essay is presented on the left side of the page, and includes an interactive table of contents on the right. Just click on the section you want to view. The table of controls also allows you to specify view and specify format. Specifying view gives the options of "scholarly" and "public" views. The main function at present is to change how Tibetan terms and names are rendered - the former gives the precise spelling, and the latter gives easy to pronounce forms.
Finally, there are interactive maps. These are easy to use. Just click directly on the map, and on right hand side you will see textual data and images corresponding to what you just chose on the map. Clicking on an image thumbnail will then give you a larger version of the image as well as its thumbnail.