What am I looking for is a great tourist guide or history book that will not only help me plan my trips but most importantly provide me with good reading and extensive amount of information.
A quick google will show you Megalithic which lists a huge variety of prehistoric sites.
Ensure you get to Orkney, which has the oldest stoneage settlement in the UK, at Skara Brae along with other stone age ruins, such as Maes Howe, the Ring of Brodgar, the Standing Stones of Stenness, cairns, duns and brochs, as well as Viking relics.
In order to plan such visits the the website of English Heritage the organisation that manages Stonehenge and many other such sites in England and Wales, or their Scottish equivalent Historic Scotland may be useful.
These have information on what current archeology has to say about such places and details on how to visit them, opening hours where appropriate, car parking and entrance fees, how to get there, facilities available etc.
For instance Stonehenge prefers visitors to book a time slot now for their visit, with people who just walk up finding they may not get a ticket.