One of the nice things in ibook application is that you can put a sign on the current page of a book or PDF you are reading, but there is no way to put a sign on which Magazine you are currently reading.
On my iBook application i got lots of PDF documents and magazines. They are all devided into various sub folders. I may read at the same time 4 magazines of different subject.
Problem is that I tend to forget what is the current Magazine I am reading in the current folder.
So I created a simple PDF page in large fonts stating "Reading here" with a large arrow Pointing to the left. Loaded it to my iBook. I simply drag it to the right of my curent reading Magazine, and no need to search it any more.
Created few of these PDF pages, and spread them through my sub folders.