Tipping is the norm in Cuba,  just like the USA etc.

If you are unsure of just how much would be the 'right' tip, ask  your rep.

In general 1CUC is fine for waitresses, barmen, maids, etc.  with maybe 5CUC for a tour guide.  No-one expects you to tip every time they bring a drink, after every meal, or even every day for the maid.  You can show your appreciation by sitting in a waitress' area on repeat visits to a restaurant. Tip the barmen once every other day or so and the room maid a little during your stay plus a larger tip on the last day.  The service you will get will be second to none.

It's easy to forget the staff behind the scenes. Don't forget that the guys making the hotel gardens look beautiful, or standing all night on the perimeter to keep you safe in your beds deserve recognition too. A few pesos goes a long way in helping these people.

Try to use your Spanish, how ever limited. too.  Simple things like por favor or gracias (please and thank you). Buenos Dias  for good morning,  and add senor for men or senorita for the ladies. Hola is the informal greeting,  much as English speakers might say "Hi." An inexpensive phrase book and a little effort will make your experience even better.  The Cubans are used to lazy travellers who don't bother learning even the basics, so when the effort is made,  it is very much appreciated.

Tip everyone.The average salary is 20 CUC a month, your beer is 1 CUC - you can afford it. You don't have to tip every drink, but certainly show your appreciation. Don't tip the taxi driver however once you have agreed on a fee, most taxis are independant  and your driver will have worked that in.