Well I like entirely too much text
Stretching resources like that tend to be scattered. I would recommend that you read through most of that because once you do you'll understand a whole lot about stretching. Finding particular stretches with pictures and whatnot is not the problem. The trick is to know what needs to be stretched and what really doesn't. There is kind of this misconception that EVERYBODY needs to stretch every muscle in their body no matter what and that's really not the case. In fact, in terms of weighlifting it can do more harm than good. I have a list of basic lower bodies that would fit in generally with the most common problems floating around somewhere. But just going somewhere and picking up random stretches is not really a good idea. It's like lifting, it does take a little planning.
I'll give you a for instance because I think it is important for you and everyone to understand the kind of misinformation you might find. You may go to a site on flexibility and find a bunch of stretches for your external rotators. So you go oh, yeah I've heard of those, I better do these
. But that site does not know you are engaging in strength training or how long you've been doing it, what your imbalances are, etc.
It could be that your external rotators are chronically tight. But for a wieghtlifter who does lots of bench work, lat work, etc. (all INTERNAL rotation) chances are the large internal rotators like pecs and lats are chronically tight and overacvtive and the tiny external rotators, the antagonists, are loose and weak. So would stretching them be a good idea? Probably not. What should you be stretching? Those tight lats, pecs, etc....
It's the same thing with these parts I mentioned you might need to stretch. I'm making an assumption that if your feel the deads a lot in your back, part of that could be tight hip flexors. I'm assuming that if those are tight the hams are too. And of course the lower back itself may need work. This is probably the case but I don't know...you have to determine that. It would be irresponsible of me to just say "do all these stretches for these parts".
Sorry to make it more complicated.