Tough one.
Invariably you will be contacted by all manner of individuals, if you haven't already, 99% of whom will be bonafide authors, publishers, bloggers etc and 1% will be nutters, all wanting to use your pictures for some project. This is where you have to decide whether you want to slug them for the privilege and risk them going elsewhere - or permit them to use your pictures conditionally / unconditionally.
It really is a case by case basis for me. For example, I have given the WFA carte blanche access to my collection
gratis, but have requested a 'small donation' from others ie: Getty Images. Students can use what they like at no charge, but I request publishers give me a little kudos for supplying the image - once again, usually free of charge. Hey - I'm a nice guy.
I have chosen the most lax setting in terms of license for my pictures as I believe copyrighting is of little value in my case and the genuine parties interested in the images, authors, publishers and the like, have always had the decency to contact me first. I realise this is not always going to be the case, but this is still very much a hobby for me and I tend to be a little apathetic towards such things
One word of warning, every so often I get a "this is a photo of my grandfather" type message posted underneath a picture - the authors of which mostly turn out to be in that 1% category I have previously mentioned.
Cheers,
Brett