Subjects... well, that's really up to you.

Obviously there is the family - but do try and take more than
just the posed shots. Let the kids play on the beach and try a
few shots without telling them that you are going to tak them.

The candid types are often much better to look back on.

Take a few general shots on the beach, of people and things going
on. If you are more serious than a family photographer, then such
shots can do well in competition of at picture libraries.

A few shots of the surrounding area and attractions are always
good for the memory in later years. For wider use, the well known
scenes have less value unless shot in special circumstances.

We usually hire a car for a few days, and that is the chance to
look at, and photograph, some of the less touristy areas. In some
countries this is not a good idea if you want to keep your
valuables - I once finished up in a very dubious area of down
town Orlando, and was very pleased to get out !

I look for natural history subjects that I cannot get at home -
Praying Mantis in Majorca in Autumn, for example. Such shots make
a fine addition to the album of even family photographers, but an
SLR is really needed in many such cases.

If it looks good or interesting then shoot it. That's a good
rule. A frame or two of film is cheap, and you may wish later
that you had taken the shot.