In reply to Rharrison:
I've not been to the Tassili, but have seen pictures of the Area which looks good. Most of the climbing has been done by french folk. There was a guidebook to climbing in the Area available in french.
I visited the Hoggar about 30 yrs ago before things went tits up in Algeria. One of the best climbing trips I've ever been on. Flew into Tamanrasset with my mate Fast Eddy - It was my first ever flight, sunrise as we flew across the Sahara.
We stayed round Tam for a few days and climbed local to there. Good climbing, some on old Volcanic plugs. Tam was an amazing place - very remote with Tourag tribesmen wandering around - Tall and dressed in blue robes.
Then we got a lift into the desert and camped near Asakrem in an area with lots of volcanic plugs which we climbed on. We climbed routes up to about E2 and they were all good. Not an area to have an accident though. We only saw a very few people there and one day a huge camel train went by. The only other climbers we saw were an Italian party led by Giancarlo Grassi - famous alpinist sadly died in an accident some time ago.
Lucky to have been there. So many memories. If you search the net there is an account of a british trip there in the late 1950's