First go to FILE, then, click on EXPORT.
There will be two options: "ImageFile(In Pixels)" and "ImageFile(InDimensions)"
Both of them work exactly the same =D (I use the pixel one ^^)
A new window will appear, there you can choose the quiality of the image, if you want it in black & white, grey scale, or like in the original page. You will be able to save as BMP, JPEG, PICT, PNG, Photoshop, TGA and TIFF formats. That way you can save your page in any size an format, it all depends about what are you looking for.
Well, that's pretty much it, I hope it helps =)
Good Luck!!!