I recently started a YouTube series on hacking. With a main focus on reverse engineering and memory corruption. I'm currently on episode 0x5 and I currently release them biweekly.
Yes, the Lena tutorials are the industry standard, if you can refer to the cracking scene as an industry. As far as I remember they are targeted towards blackhat crackers but the information is still valuable even for aspiring security researchers or whitehats.
I understand the paranoia, but quite frankly "unknown provenance" is just FUD. Countless others, including me, have used them with no problems. Due to the demographic of their intended audience, I doubt any maliciousness could remain undetected and unannounced for long --- trying to hide something from a community of reverse-engineers tends to be rather difficult. ;-)
Fair enough, it just hit too many of my "this seems sketchy" twitches. Would be nice if they had some mpeg 4 or whatever as well. I could break out ffmpeg but can't remember how to convert so I just don't bother. Other things to do in either case so no big loss.
If you want to practice your reverse engineering skills in a legal manner, check out crackmes.de: http://crackmes.de/
tuts4you also has a nice crackme/unpackme section.