* Who is it best to do it with (i.e. friend? stranger? internet contact?
I find that it is sometimes easy to do it with a friend...or internet contact
* Where did you do it? Hotel? Home?
Home where you are most comfortable...unless the third person would be more comfortable somewhere else.
* Was it good?
Its incredible to have two people to play with.
* What did you do during it?
I did it all...if some one needs a hand you can offer it to them

* How did you arrange it?
I talked it over with my friend who thought it would be a good idea for another friend to join us (we werent in a relationship...just good friends)
Be prepared though if it doesnt work out like you antipated. Sometimes people become uncomfortable having their s.o. kissing or touching someone else. Be sure you want to really have a threesome. Once you do have fun. :-)