design advice please

hi there folks, i am new to the world of home recording and i have a problem. my home recording and listening area is in one small room (10 ft long by 8 ft wide). there is no back wall (it is the 2nd half of a double room). It looks like this (U - basically a rectangle room without the back wall.) the open end is facing the rest of the room which is being used by my girlfriend. the open end is also facing the street where a lot of sun comes in from 11 am - 4pm. i want to use my share of the room to record voice, acoustic guitar and midi. my main problems are 1. if i put my desk (with computer, mixer, speakers and mic) facing the front wall (the bottom of the U) then my back is to the sun and that is not the best thing for my computer screen (5 plus hours per day). 2. if i put my desk right up at the top of the U, i am worried about my mic picking up street sounds when i record. should i just put up a divider à la thick curtains, drapes to separate the room when i am recording? as i also use the room to practice (vocals, piano) i want the room to be as useful as possible while being able to record a good quality demo. i am renting the apartment, the room is untreated, no carpets pannels or any other sound absorbing materials. the door is on the lower right side of the (U.) any advice you could give would be greatly appreciated. thx b4one