A eulogy is a speech that celebrates or pays tribute to someone who has died. A eulogy is quite similar to an obituary, but it is intended to be read aloud before a gathering of the deceased’s family and friends. This spoken tribute is intended to honor the person who has passed, as well as connect with the audience and share in the memory of the deceased.
See also: How do I write an obituary?
Timing: Keep it relatively brief, a few minutes is usually about right. For a five-minute spoken eulogy, aim to write approximately 500 words.
Organize your speech: Create a structure that is easy to follow, such as chronological, reverse chronological or based on a theme or metaphor.
Write for speaking: Don’t write in a formal tone, write the way you speak. Consider speaking from notes, rather than “reading” full sentences directly in order to keep your delivery natural.
Practice: Rehearse delivering the eulogy and get feedback on your speech in advance. Speak slowly and clearly. Breathe normally and have a glass of water handy.
Have a back-up: If you feel overly nervous or get emotional, you may want to have a back-up speaker standing by. Let that person read your eulogy before the service, so they will be prepared. (This could be the funeral celebrant.)
For further reference: http://www.obituaryguide.com/eulogies.php