IANAL, but I'm pretty sure you can trademark titles. An example is the "X for Dummies[1]" series that has at least threatened to sue people[2].
People currently associate "Learn X the Hard Way" where X is computer related to your lcthw project. If you let other people use it, that distinctiveness will go away and it will likely not be something you could trademark
People currently associate "Learn X the Hard Way" where X is computer related to your lcthw project. If you let other people use it, that distinctiveness will go away and it will likely not be something you could trademark
[1] http://tess2.uspto.gov/bin/showfield?f=doc&state=4009:ae... [2]https://www.chillingeffects.org/protest/notice.cgi?NoticeID=...