The following helped:
http://www.guardian.co.uk/travel/2008/mar/20/greek.islands.guide
As did,
The port of Lavrion in southern Attica is being increasingly developed as a ferry port, especially for Cyclades routes.
The closest islands, suitable for a day trip, are located in the Argosaronic (or Saronic) gulf: Hydra, Aegina, Poros, Spetses and Salamina.
Day trips to the Corinth Canal, the theatre at Epidaurus and to the ancient sites of Olympia, Delphi and Mycenae are easy with a rental car. Other towns along the Peloponnese such as Nafplion are charming and worthwhile.
I plan to be there 18th-23rd March staying next to The Acropolis. Flying in early and out late. Therefore with time to spare, do you recommend I see the islands? Should be two fo use, so interested in cheap (hostels?) available on those islands. How much are the ferry trips/duration?
Thanks