Recommended translations:

• Plato's Parmenides, trans. Samuel Scolnicov (Berkeley, 2003).
• Plato's Parmenides,  trans. Albert Keith Whitaker (Focus, 1996).
• "Parmenides," trans. M. L. Gill and Paul Ryan in Plato: Complete Works, ed. J. M. Cooper (Hackett, 1997).

Excerpt:

Cephalus
When we came from our home at Clazomenae to Athens, we met Adeimantus and Glaucon in the market-place. Adeimantus took me by the hand and said, “Welcome, Cephalus, if there is anything we can do for you here, let us know.”

“Why,” said I, “that is just why I am here, to ask a favour of you.”

“Tell us,” said he, “what it is.”

Online:
Amazon (Recommended Translation: Scolnicov)
Amazon (Recommended Translation: Whitaker)
Amazon (Recommended Translation: Gill and Ryan)
Project Perseus (English, Free Access)
Project Perseus (Greek, Free Access)