If you want to make a browser based game then maybe look for inspiration in some of the established browser based games out there that are popular. Personally, I rather enjoyed playing Travain for a few months and there was another one I don't remember the name of that was some space empire. See what works, what you like, what inspires you. When you have a fairly solid outline of what direction you want to go, start doing what you can and come back to ask questions about whatever might be stumping you. Questions more like what the best way to handle turn processing might be, considerations for securing data, and the ever popular questions about how to find or create art assets. Specific questions that are aimed at tackling specific problems for a project that you already feel passionate about. Because, it's going to be tough for anyone to give you ideas that you'll be passionate enough about to to see a project through. It's a lot of work after all.

I made a suggestion a while ago on gamedev you can use;

http://www.gamedev.net/topic/656783-f2s-group-rpg/

You could use unicode on a grid to represent units and buildings and resources. I'm going to make this multiplayer browser game myself eventually. But maybe you'll get some ideas.

Apartments regenerate 10 housing each turn, which restore 1 unit of labour in a worker each.