A lot of interesting stuff is made available at Jihadica now.
I picked this paper to start with:
"Foreign fighters in Afghanistan and Pakistan after 9/11"
I found it interesting, although, as to one of its main conclusions, I don't see that much tension between statements that al-Qaida, after the failure of the Iraqi franchise, redirected its focus to the Afghan theatre, while the Afghan theatre was always important to it.
Back in 2003, bin Laden said, "Get the Americans in Iraq before they get us here." They won four years, and Afghanistan lost four years "in the mean times." And then the ball was bouncing back in Afghanistan again.
But the paper (actually, rather the transcript of a presentation, unfortunately without references) is well-written, and Anne Stenersen, armed with the required language and analytical skills has sorted through a hundred "martyr-biographies," of fighters who died since 9/11 in Afghanistan.
If this much wasn't enough to get you to make your move, here's an interesting excerpt:
"...a large majority (about 70%) was physically present in Afghanistan at the time of 9/11, and chose to participate in the fight against the US invasion before withdrawing to Pakistan. This means that the foreign militants who managed to flee the US-led invasion in 2001 also became the core of the new contingent of fighters that have been active in the area after 2002 - at least up until 2006. Today, many of these foreign fighters have of course been killed, and the question is to what extent they have been replaced with new militants. Since I am only using open sources in my studies, it is too early for me to tackle and discuss this question."