The poems give you clues to unlock each trove.

Read them carefully.

All trove passwords are completely lowercase!

Have fun!

Just solved all three. The third one seems like it could be a lot more difficult than the other two...depending on the solver's knowledge of -- ahem -- certain functions of google. Was that intentional?

Well, it is optional stuff — hopefully it should be easy to find. I always offer to give people hints. And may add some by the weekend. 

I've solved the second and third one almost immediately (that's a great reference on the third by the way!), but I have no idea what to make of poem one. Can you give us a clue, Tom?

The answer is IN the POEM. (As in, you need look nowhere else.)

And the last line is most important clue to where to look in the poem.

I am not one to decipher things, but the second poem is a dead giveaway. The first and last ones are confusing. Do the pictures have anything to do with the answer? Also, are each of the passwords only one word for each zip file?

They are each one lowercase word, a password corresponding to the other zip file.  Just to cover each for everyone (HEAVY HINT SPOILERS AHEAD):

The FIRST, look at the poem, and consider what "beginnings" you should look at. Your INITIAL guess might be right.

The second, people should LOWER their expectation in this CASE.

The third one is a reference to the movie War Games. Google that for the obvious password.