I will try and help until someone more knowledgeable comes along!
The buildings:
Main Building : This is concierge level only. It is also known as RPC. The regular rooms have been rehabbed and they are/will be doing the suites next.
Outer buildings
Big Pine Key
Boca Chica
Conch Key
Sugar Loaf
Sago Cay
Of the outer buildnings
Sugar Loaf is also concierge only! It is next in line for rehab and will close shortly. Our opinions are that the outer building concierge level will then relocate to another outer lodge building for the duration and move back into Sugar Loaf when it is completed.
As for the rest,
Conch Cay is rehabbed and done. It has nice garden views (and also some theme park views). It is a further walk to the Main Building (but it really isn't far at all!) and is closer to the quiet pool. A walk to the Main Pool. This would be closest to the boat launch.
They are working on
Big Pine Key. It should be done soon, actually. This is close to the Main Building and both pools. The garden views are good, but there is a chance of a garden view overlooking the quiet pool building roof.

Not as nice if you get that one.
Sago Cay is close to the main building and the quickie meal location, Gasparilla Grill. The garden views here could be of the marina!

I've heard a GF regular continue to say that this is her favorite building. The other side faces the monorail side I think. It is a short walk to both pools, but it is closer to the quiet pool.
Boca Chica is also under rehab now? Or soon. One side is considered Lagoon/Theme park and the other has nice garden views facing the quiet pool. I think it is still a quick walk to the Main building and it is close to the quiet pool. A walk to the Main Pool. I like this building.
So closest to the main building and monorail: Big Pine Key, Sugar Loaf, and Sago. Closest to quiet pool: Boca Chica, Big Pine Key, Sugar Loaf, and Conch Cay. Closest to the Main Pool: Big Pine Key and perhaps Boca Chica.
Closest to Gasparilla's: Sago and Sugar Loaf.
Hope that starts you out and I didn't forget or mess anything up! Have a great trip!