I am a real beginner in LyX and I want to insert a small image into the header. Actually I want to insert two images. But let's begin by one. I have no idea how to do this and would appreciate any help.
In the Lyx help file Extented Features, see section 3.5 on Fancy Headers and Footers for the code which will allow you to insert an image into the header.
Probably this link would be helpful for you: