Hi SW
It's quite likely to have been a Sparrowhawk if you've seen them around - it's probably got a nest somewhere and took the sparrow to feed to the youngsters.
To upload a picture you first need to re-size it - I'm not great at this but hopefully this'll help.
After you've done any other work on your pic (always a copy mind ) and cropped away any part of the picture you don't want, you can then re-size it. But
don't crop to get the file size you want.
How you actually do it depends on what programs you have.
In Windows 7 you can right click on the image and there's an option to re-size (choose the smallest 800x600 - you can go bigger 1032 on the longest side I think, but Windows doesn't give you that option!). Adobe Photoshop: you have a better choice there, in the Image menu: Resize, you can actually choose the size you want, and the quality... always select medium.
Alternatively you could download the free program called Picassa.
I hope one of these ideas work for you. If not, try posting in the
Computer subforum - I'm sure someone will have more suggestions for you. There's loads of methods depending what software you have.
If you need more help, please don't be afraid to ask.
D