Do you plan to visit these places with public transportation?
Or will you have a rental car?
Using public transportation, won't give you any flexibility to see enough.....

Unfortunately, we be using public transportation throughout this trip. Yet, we hope not to miss any impt places of sight. Does it matter if we go Olympia or Delphi first? Need all the help & directions to get around. Thanks.

Your main problem here is the connection between Olympia and Delphi. Although Athens to Olympia is not so straightforward either ( you have to go from Athens to Pyrgos, then get an other bus to Olympia, and I think bus ride takes a good 4+ hours), the Olympia to Delphi part is the most hard. You have to go on Pyrgos, get a bus to Patra and try to time in an arrival there with a departure towards Itea or Amfissa. there are two departures per day from Patra and only one on Sundays. Then from Itea or Amfissa, other bus to Delphi. Delphi to Athens very easy, but the point I try to make is, that Athens to Olympia and Olympia to Delphi are mainly days spent on transit, so you would have to spend 2 nights on those places anyway due to travel logistics!

Alternatively you can go on an organized tour, there are some reliable companies in Athens offering a 3 days classical tour, that goes to Epidaurus, Mycenae, Olympia and Delphi.
It is a rushed tour, but you will see everything that you wanted without having to take local busses and have the bstress of schedules, departures and connections...

Have a look at Key Tours, Chat Tours or GO Tours.

As we are on a budget, don't think that we be joining the tour. Any websites or help where I can find timetable guide for the buses from Athens to Olympia, Olympia to Delphi, & back to Athens?

Here are the websites of the local KTEL companies ( private bus company serving the whole of Greece)

Fokis area ( Delphi)

http://www.ktel-fokidas.gr/?module=default&pages_id=2&lang=en

Achaia area ( Patra)

available only in Greek

http://achaiaktel.gr/?module=default&pages_id=2&lang=el

Ilia ( Pyrgos- Olympia)

available only in Greek

http://www.ktelileias.gr

As Mariha explained the connection between Delphi and Olympia is a bit complicated....

Thanks Clausar. Went into the websites to look at the bus routes and timing. Think its really too tough to go free and easy by public transportation! Esp the part between Delphi and Olympia as Mariha explained.
Anyone have any local tour company to recommend for the tour? Guess we have to sign for a local tour (hopefully conducted in English) and scrimp on other portion of our trip.

Jo
i already recommended local tour companies...

Key Tours
www.keytours.gr
( for some reason i can't open it, it requires username and password, if you can't either pls let me know)

Chat Tours
www.chatours.gr

GO Tours
http://www.gotours.com.gr

All 3 companies are excellent and offer a great reliable service. All tours of course are offered with english speaking guide.

Sorry. Missed out your recommedations on the grp tour on the earlier post. Shall compare the 3 tours and most likely chose one from there! Thanks

On 2nd thoughts, wld u guys recommend we take separate trips to Olympia & Delphi? As Delphi is abt 2 hrs from Athens, should we depart real early for just a day trip to Delphi or do a overnight trip?

You could do 2 separate trips while based in Athens.
Delphi is 2,5 - 3 hours away , i would recommend an overnight there, so that you can visit the archaeological site early in the morning, when it is relatively quite and not hot.

With the local busses you can reach nearby Amfissa, Itea and Galaxidi, so that you will see bit more than just Delphi

Olympia is 330 km away from Athens, an overnight there is a must, it is not doable in one day.

Delphi is 3 hours from Athens. I would spend the night.

Anybody has a rough guide of the bus ticket prices from Athens to Olympia & Athens to Delphi. Will like to make a comparison with a grp tour & compare if the savings are significant or not

Delphi appears to be 15€ one way.
http://www.athensguide.com/practicalinfo/busschedulesB.htm