Brother In The Land (Puffin Teenage Fiction) by Robert Swindells. Post apocolyptic.
The Dead Of Night (Laurel Leaf Books) by John Marsden, first of a great series. Australia is invaded, teenagers act as resistance.
The Kin: Suth's Story Bk.1 by Peter Dickinson. 4 books in series. Stone age, lots of primative skills.
Chronicles of Ancient Darkness, mentioned before.
The Dead Of Night (Laurel Leaf Books) by John Marsden, first of a great series. Australia is invaded, teenagers act as resistance.
The Kin: Suth's Story Bk.1 by Peter Dickinson. 4 books in series. Stone age, lots of primative skills.
Chronicles of Ancient Darkness, mentioned before.