"The dog eats there."
Translation:Il cane mangia là.
"là" and "lì" have the same meaning.
There are some fixed expression with one or the other like
"Vado di là" (here "là" = the other room)
"Sei lì lì per arrenderti" (you have almost surrendered... "lì lì" = almost)
Wordreference can help you with all the idiomatic uses of the two words. :)
Not so far, I simply look for random links when there are issues. I am not a language teacher. :)
Of course wordreference is a good dictionary.
The best thing would be that you tell me the sites you would like to use to study, and I can tell you if they are correct or not.
The ones that can tell if they are easy to understand are you. :D