Do you have Photoshop? If you do you can upload and resize pictures of existing furniture (and even recolour them if, for instance, you are thinking of reupholstering) that way, then drop them in to your room design. SketchUp is free and a lot of people find it the easiest interior design software to use. Have fun!

Sketch-Up and Layout..with an add on rendering package....works a treat! There are loads of on-line tutorials for trouble shooting...

That good software design is great, I asked a company to develop something similar for me and it stayed similar but I had more options in the menu for interior modeling thanks to these dedicated development team that helped me finish the project.

Well do make sure you get your ideas/drawings safety checked before you start work or order anything! Some apps like magic plan and house design work on iPads quite well - sketchup for pc and for one off custom pieces of furniture- Jali.co.uk and Tylko .com are useful.