Ignore dcomposed. He has issues.
There's a lot of old comics you can search for at your local shop... I think DC and Marvel both released tribute TPBs shortly after the attack with various creators contributing small vignettes. I wouldn't say it's great literature, most of it is pretty heavy-handed, but it's respectful and it serves its purpose which is to honor those who died. Some of it is small stories, and some of it is just pin-ups or one page affairs. I found the smaller, more concise pieces were usually better. Despite a lot of it looking pretty dated now, there are some good pieces done by creators such as Will Eisner, Alan Moore, Joe Quesada and others. I really forget the names of these TPBs. I think the one by Marvel is called 'Heroes', and there's a TPB called '9/11: Writers respond' and '9/11: Artists respond' or something like that.
The guy who writes Amazing Spider-Man also did a tribute issue (v2. #36 I believe) and it's easy to find because it has an all-black cover. It has Spider-Man going to the WTC wreckage and helping out, and the issue has good intentions and some great art, but likewise it's very heavy-handed and dated now. Still worth checking out if you have the money and time, though. Hope I've answered your question.
