Hi Marion,
I have been travelling to Cuba since the 1990's & my last trip was with Travelsphere last year and the itinery is, essentially, unchanged. Our tour manager was Carolyn (I was first in Cuba before her) & the guide was Maria (Someone has mentioned Hector who we were due to have but he was plucked from us to guide some vips but I have used him before.) Both guides were very knowledgeable.
On the hygiene front sometimes soap & water at some stops can be a bit sparse so carry some hand gel/wipes (I do this even in the UK).
Hotels are the same as I used except for Havana where you are in the Seville. I was in Hotel Nacional - very nice but a $3 - $10 taxi ride away from the old town (La Habana Veija). Taxi fares were "negotiable" and £10 was in the day and $3 was after an evening in town.......Hotel Seville has the advantage of being very central so it is easy to walk to the main highlights. The Brisas hotels in Guadalavaca & Trinidad are of the "all inclusive" type and whilst not my ideal cup of tea they are very comfortable and food is of the buffet variety.
I have used the $ sign but tourist currency is the Cuban Convertable peso (CUC). You can only get this in Cuba & I usually take sterling & change as needed. However, in some of the smaller or more remote hotels they may not carry a lot of currency so best to change in places like Havana or the Brisas hotels. I have never taken travellers cheques but believe some people have had difficulties with these.
As for what so see then it depends how much of a revolutionary you are! You will be taken as part of the tour to main sites in Santiago de Cuba & in Havana and there was an excursion to Santa Clara where the Che mausoleum is situated. A must for me and I think most others found it interesting.
On the subject of excursions there were:-
1) A visit to Tropicana nightclub - personally I have never been & I prefer to find something a bit less touristy - it is quite expensive,
2) A harbour sunset cruise in Cienfuiegos - I passed on this. I am a photographer & the pictures & the light were on shore,
3) A tour of some botanical gardens. Take your mossie repellant - I forgot & suffered,
4) I walk at Los Jasmines down to the tobacco fields - you do not have to be a smoker to find this interesting.
As regards the trip generally then back in the 1990's a few of us in a mini bus would roll up at any wayside halt where we thought there was coffee and loos. With the need for hard currency the tours are far better catered for now with purpose built wayside halts at the points tour buses cross at lunchtime etc.
Out in the countryside then lunch would usually be a Cuban sandwich of bread, cheese & ham but expect there to be variations (shortages) on what is sometimes on offer. Hotel meals were fine and the locals are encouraged to set up in businesses so there are many private restaurants.
A bit of background reading on the politics would help (unless you are already familiar) and most decent guidebooks will give you this.
Rationing is the order of the day for Cubans unless they have access to hard currency and hard currency shops are not always well stocked especially with basic medical stuff. Take any painkillers, immodium etc etc you think you may need as you will find these difficult, nay impossible, to buy.
If you have Hector then on one tour most people donated an item of clothing - Hector then took these back to the east of the island (the poorer area) & redistributed. I usually go through the wardrobe and take a few items I no longer want for wearing & redistribution. More space in the case coming back!
It is expected that hotel toiletries will be nicked & redistributed - ladies are always asking for sabon (soap).
Finally if you want to buy cigars then every tout on the street has a relative who works in the cigar factory and can thus get you a bargain! Nothing on the street is the real thing! There are plenty of bona-fide shops, especially in Havana, where you can buy the real thing.
Anything else then feel free to ask.
Ian