Generic answers will give you some insight, but detailed answers require more info from you. For example, how experienced are you in model railroading? What's the largest locomotive and equipment you plan to run (even if just for now)? What control systems are you planning to use (conventional, Lionel command of some sort, MTH DCS, etc.)? Do you already have track, and if so, what type? Are you comfortable working with free track planning software like SCARM? Do you expect to get scenery and buildings into the area you have along with 3 main lines and multiple passing sidings? How good is the lighting and electrical work in this room?
These questions will tell us what size curves and switches you either must use (due to equipment limitations) or want to use because you have it. In an 11' x 11' room, that is probably the most important question to answer. Also, if you don't have to run loops (or choose not to), you could build a nice "U" shaped switching layout in that room with a small yard on one side, an interchange (and even smaller yard) at the base of the "U", and a small industrial area on the other side that even leaves a little room for scenery and structures.
Chuck
I grew up working on my dads 8x20 Super O layout (conventional lionel). Im a civil engineer in the transit construction industry so i have a fair amount of knowledge on the whole process from benchwork to operating
Ill be starting my own and already have several MTH PS2 consists. (i have a DCS explorer, but waiting on the new WTIU).
All engines are O31 (subways and trolleys are O27), i may havea need for slightly larger radi down the road
As far as track goes, i have a mix of fast track, O27, and super O. Im leaning towards going Menards for the Mainline routes, and using the fastrack for a trolley line, and O27 or Super O for Elevated
I have been using SCARM, but need to brush up on how to create the benchwork in there
Id like to minimize the number of switches i use, in order to simplify my power configurations. (for whatever reason, i dislike switches between loops!!!)