If you're looking for a poem to read at a funeral there are certain things you should be aware of first. Not everyone is going to feel the same way about the loved on that you have lost so the poems may seem irrelevant to them. Long funeral poems are very difficult to get through without plenty of support and practice and choose the poems you want, not what everyone else thinks you should read. A lot of people choose to read passages from the Bible rather than a poem because they think that this is more appropriate. My feelings are that you should go with what feels right for you and what your departed loved one may have wanted.
Some of the best funeral poems are quite short and very moving, but be careful not to get too morbid when choosing the right one, this makes it a lot harder to read. Here is a quote from John Oxenham "As you love me":
As you love me, let there be
No mourning when I go,
No tearful eyes,
No hopeless sighs,
No woe nor even sadness!
I think that this is a beautiful tribute to a person's life, the poem is 5 verses long and goes on to announce happiness and joy. When you are choosing a poem to read at a funeral remember all of the good and the happy times you had with that person, even now whilst suffering from grief, you'll probably find yourself smiling.
Funeral poems can also go another way, instead of a tribute to the life of your loved one you could also use a poem which expresses what they may be saying to the ones they left behind, take this example from Dorothy Parker's "But not forgotten"
I think no matter where you stray,
That I shall go with you a way,
Though you may wander sweeter lands,
You will not forget my hands,
Nor yet the way I held my head,
Nor the tremulous things I said.
Once you have read through a few poems it will become much easier to decide which direction you would like to speak from.