Forgive me, I'm self-teaching a move to ASP.NET from Windows forms...questions questions...

I want to insert a list, content of which will depend on the user or role. So I think I want to insert some HTML which I'll build in a function somewhere ... but I can't figure out how to get it onto the page in the right place. I want it in one of the divs in my master page. What do I need to put onto the page to allow me to build a string in codebehind (presumably Page_Init) ???

Firstly, does that make sense? Secondly, am I going about this in the right way? Thirdly, can anyone nudge me in the right direction - I'm sure it's an "easy when you know how" moment...

Cheers!