Day trips from Athens

These are the most popular day trips ex Athens
1. Sounion [afternoon] organzied or not [you can easily take the local bus]
2. Delphi [organzied or not i.e. you can be part of a group tour, or take the regional bus ktel, yourself]
3. Argolis [Corinth, Epidaurus, Mycenae, Nauplion] - easier visited on an organzied tour, or hire a car for a day or 2 visit, with an overnight in Nauplion.
4. The Saronic Gulf islands [Aegina, Poros, Hydra], - better visited individually on yr own IMO. [may work out cheaper and you have more time to stroll at yr own leisure]

It is worth buying a guide book to read up on the abv, as well as the places you will be visiting in Athens,

Hi Scot,
Depends on what you are interested in. If you can hire a car, drive to Korinthos (Corrinth) to see the canal and if they are open try one of the most exciting bunji jumps in the world. Turn off the motorway on the exit signposted Loutraki and Korinthos for the best view. When finished (if alive) make a left once over the bridge (sign posted Epidavros) and after about half a mile turn left (signposted old national road) and take a look at the Isthmia bridge over the canal - it drops into the water to allow ships to pass. There is a small port and a couple of tavernas - service better on the Athens side. Don't bother with the town of Korinthos itself. But if you are into archeology Ancient or Agra Korinth nearby are worth a visit (closed in the afternoon), or even Epidavros about 40 miles further to the south but really worth the journey. If you keep driving west towards Patras you can even go up into the mountains by road or rail (the Dhiakofta rack & pinion railway) and visit the ski centre at Mount Helmos - naff all there but you can say you've been 2355m up a mountain. Looking through my window this morning there is snow up in them thar hills! If visiting Myceanae stop for a meal or drink at the Fair Helen. Check out the photos on the wall and the entries in the guest book. Could tell you all about it, but I won't!
If you are a gambler there is a great casino in Loutraki (as well as loads of bars and a pretty seafront).
I totally agree with bizwiz. You will be able to pick up a guide book in Athens but I do recommend Rough Guides or Lonely planets ones.
Don't bother with the former Olympic Games sites - it will put you off London a couple of years after we've hosted the games!
Ask for Amstel, Mythos or Hinekin(!) if you like beer (rarely able to get decent draught) or a half Kilo of wine (the bottled stuff is very expensive).
Check out day trips from the port of Peraus (numerous spellings).