I just got to disc 3 and I am at the part right after Lindblum where you get the boat for the first time. Without giving any spoilers (please) would this be a good time to do all the sidequests or should I hold off for a little bit?

Thanks

It's as good a time as any to start doing what you can. In fact, definitely better than waiting until Disc 4, when the World Map gets covered in Mist again.

Disc three is the best time to do most of the sidequests. More specifically right after the events in Mount Gulug and when you get the Hilda Garde 3, just before you head to Ipsen's Castle.

This part is the ideal time to do sidequests since you have access to an airship and there is no mist or Iifa Tree roots blocking areas. It is also ideal to level your characters or preferred characters to roughly around lv.50 since things are going to get harder from there on. Any further and you won't be able to come back until the start of disc 4 and you'd have annoying mist everywhere.

You can get Ultimate Weapons for Zidane, Dagger, Steiner, Freya and Quina by completing some of the sidequests and secrets. While you can do most of the sidequests later, its just better doing it at this time. :]

You won't be able to get Zidane's Ultimate Weapon til disc 4 though because it's found underwater with a sea chocobo where the Shimmering Island is in disc 3 - because the island still existed at that time, and is only destroyed after the party goes to Terra it's impossible to get at that earlier point in the game. :p).

Yeah, that's a good point-- I was actually driving myself a bit loony the other day because I was replaying the game and it took me a while before I remembered that one of the foaming waters just wasn't accessible until Disc 4.

Disc three is a great point to start doing side quests if you ask me. Besides if you wait to much longer you will run into some...issues... with the world map.

There really was no need to revive this...