beginners query about asp.net website management

[skatopia]

I recently started managing a asp.net website. earlier my employee had simple HTML and one php website and I can easily work with both of them and can do medium level of customization like add/edit things. But now i have asp.net website and its killing me. All the files are precompiled but I have source code. Please tell me how to add edit content etc. Consider me as a student with required knowledge of HTML, php and css.For example I was told to add a table in a page, I had html code for same but did not know how to do it. I tried adding it in HTML file and aspx file but no use. Than I add it in files in bin folder and website started giving error about precompile index file first. Now when you know my understanding about asp.net is nil, please, guide me to save myself from embarrassment I may face. Although its not my job M into marketing but during interview I said that I can do it all w/o knowing they have asp.net for me. Also let me know the tools I require like visual studio, iis etc.