Making Many Maps from OSM for a project (how to attribute)

The cc-by-sa states: "You must keep intact all copyright notices for the Work and give the Original Author credit reasonable to the medium or means You are utilizing by conveying the name (or pseudonym if applicable) of the Original Author if supplied". From my understanding, in a book it might be sufficient to state: "all maps (c) openstreetmap contributors, cc-by-sa 2.0" at the end or beginning of the book, where other credits are given. In a tv-feature the reasonable way to give credit might be the closing credits, and so on. I am not a lawyer and this is not legal advice but my personal interpretation (matured in discussions in the community).

OSM states in its Wiki for the how:

• If you are using OpenStreetMap tiles (e.g. Mapnik or Osmarender/tiles@home), we request that your credit reads at least "(c) OpenStreetMap contributors, CC-BY-SA".

• If you are using OpenStreetMap data only, we request that your credit reads at least "Map data (c) OpenStreetMap contributors, CC-BY-SA".

And for the where it states:

• For a browsable electronic map (e.g. embedded in a web page or mobile phone application), the credit should typically appear in the corner of the map, as commonly seen with map APIs/libraries such as Google Maps.

• For a printed map, the credit should appear beside the map if that is where other such credits appear, and/or in the "acknowledgements" section of the publication (often at the start of a book or magazine).

That is ok for the OSM data alone, if you create a new map based on OSM data it is a derived work and you have to publish it under a CC-BY-SA compatible licence (if you publish it at all).
I recommend you reading the licence properly and asking some lawyer if it is not clear.

I like it very much when you are linked to the actual location on Openstreetmap as well, using a link like one of these:

• http://osm.org/go/0bCzx1z- (Copy the link in "short link" at the right bottom corner)
• http://osm.org/?lat=59.315&lon=18.068&zoom=11&layers=M

This lets people easily change stuff in the map if they want, I know almost no one does this but I'm guessing it would probably help you in your work if you keep track of where you took the map.

I hope the history project turns out great.

Yes that's fine as far as I understand it. These are the sort of uses that lots of us had in mind when we joined the project. It is probable that the required crediting (wording) will change at sometime. The wiki will explain a bit more.