Hi plbab,
My advice is go to a hobby shop, & see if they have some books with published track plans...(you can find these on line too - amazon.com, or
www.walthers.com )
Atlas has several books of HO track plans, or look for titles like 101 Track Plans For Model RR's, or HO RR That Grows, or Small RR's You Can Build, HO RR From Set To Scenery...& I'm sure there are others.
These should give you lots of ideas about what you might want to do with your available space
Back issues of Model Railroader magazine, if you can find these, also have a lot of ideas.
Model Railroader also has an annual publication called Model RR Planning. (you can find these in a lot of hobby shops) They have lots of great ideas, especiallyu for spare room type situations
There's also a Track Planning For The Future forum here at The Gauge. If you post your room dimensions, whatever ideas you have, & I'm sure you'll get some feedback.
Good luck to you, & keep us posted on your progress!