I had a standalone headboard and I had a handyman secure it to the wall for me using a simple U bracket. The U part is squared like a u and fit around the leg, just under the wider part of the headboard. We used drywall sleeves first, and then screws to ensure it would be well-anchored and we never had an issue. If you have brick or rough stucco or plaster, you might have to anchor it to your existing bedframe. The one I used was very similar to this one...but it was a clean U shape http://www.zillarac.com/Zilla/U-Bracket.aspx

Good morning Marinalabib. You can do exactly what NK interior design is saying and I totally agree with him. The alternative is that you use a vinyl which is a wipe able fabric. To have a more sumptuous feel is to go for a fabric with a treatment, but you have to remember that your hair will have natural oils in it and this will stain the fabric. This is just general wear. Please do get in touch if you need any more information. Have a lovely day.

This is extremely large! Your problem will be that sheet materials like chipboard or mdf which would normally form the structure of the headboard come in 2440mm x 1220mm. This means you need to join it. Joining then upholstering would be unsuccessful unless you are doing it in situ. I would talk to s local upholsterer if I were you.

A few photos for inspiration, with and without headboard. Also, some with curtains rather than blinds. I do think a rod/rail as high as you could get one (below the corner beam), running the whole width of the window wall would deceive the eye re: the proportions of the room. (See pics below) Does the bed you've chosen lift up from the bottom? I think any side storage drawers would be a pain. Finally, have a look on apartmenttherapy.com. Some great advice for small space bedrooms and living in general. Good luck