Lia, why didn't you tell us that in the first place? Were you seeing if we could guess what was in your mind? No fair! Now that we know your love of learning & prep, it's a whole different story. Also, it helps us when you "Recap" information supplied on previous threads -- so we don't have to hunt back to get key information. Burrowing into your backlist, I now find that you are planning to go in June 2018, so you'll have plenty of time to read up. I also find that I recommended a number of Guides & references to you, back in July, and that you say that (like me) you want materials that have more "evaluative content" than just logistics -- where to rent cars, what busses/trains to take etc. For the benefit of other "new readers", Lia currently has Rough Guide, Lonely PLanet, Blue GUide, Cadogan's guide & Michelin Green Guide. If you do enough digging on this, I think you'll have plenty of material to enjoy those sites on your own. I also think many people enjoy t aking the BUS from Athens to Nafplio, spending 1-2 days just enjoying the Old Town & surroundings, then only renting a car when you want to go farther -- to Mycenae and Epidaurus plus Tiryns, NEMEA, an overlooked gem, and Asine... a darling little cove beach right by the ruins).
I'm sure I gave you the Superb noncommercial Nafplio Website before - http://www.visitnafplio.com and the fab photo album by our Ace photog-poster, "Stanbr" - https://www.flickr.com/photos/stanbr54/sets/72157632094108982/ for the area. For NEMEA, this website tells about the revived Games PLUS all archeology - http://nemeangames.org Also fine links on TIRYNS, which is just 10 minutes outside of Nafplio - https://hubpages.com/travel/palace-of-tiryns and ASINE - http://www.ermioni.info/tolo-asine I find this "secret beach" (also called Kastraki) a wonderful finale to a day of ruins-rambling. 2 small cove beaches, 1 sandy 1 rocky, a friendly taverna perched just above, where u can change in the restroom... swim & Sun, then enjoy sunset and a fine fish dinner.
Tips re the others: MYCENAE - get there before 9, because flocks of tour busses arrive about 10; go to Museum first, helps to orient you. EPIDAURUS - arrival time not as critical, because site is so big & spread-out, crowds not as much of a factor. MAIN thing is theatre ... the rest of acreage is rubble not that well-signaged... and museum not notable; best pieces are in Athens museum. But as noted before, don't miss the ancient Mycenaean bridge by roadside, en route.