Intrigue, welcome to the forums.
This is a big question. I don't think we can answer it in one post.
Please take a look here: http://owl.english.purdue.edu/handouts/grammar/g_seqtense.html
I haved worked here since June: I started in June and I am still here.
*I am working here since June: non-standard. You should use the one above. I am working here NOW.
I will have done... - at some point in the future, it will be complete.
I will have been doing... - at some point in the future, I will still be working on this, and it will have been going on for a while