Hi Jan,

K8 is right, the best way to start is to tape together your armature with masking tape, I tend to cover the whole armature so that the armature is solid and immoveable. The masking tape surface also acts as a well keyed surface. 

The easiest PM is to tear and layer newspaper.  The paper is lovely and flexible when covered in paste and is cheap to use.  Don't make the paste too thick, it is best at about the thickness of egg white (Catperson's brilliant description).  You can layer several layers before leaving to dry and layered paper takes less drying time than pulp.

If you then want to try pulp to sculpt onto your dolphin then make up a batch (there are several recipes on this site). 

My personal favourites are newspaper pulp for large areas and tissue paper pulp for fine modelling.  These are both variations on David (dopapier's) recipes.  Both sand down well and are easy to make up.

I tear the paper into small pieces and soak in water, I then put an old hand blender into the pot and whizz up until I have a soupy blend of paper and water.  I then dump the whole lot into a colander (over the sink) and squeeze out the water, either by hand or with a potato masher.
When you have removed as much water as possible you will have a bowl full of damp granules that look like TVP [veggie meat substitute].  Mash this together with your paste and a filler like ground chalk until you have a clay like mass.  I do this by feel but usually use 2-4 tbsp's of filler for about half a newspaper and I keep adding the paste until I feel that I have a texture of pulp that I can work with.

Pulp will take much longer to dry, depending on the atmosphere of your drying space, warm with a through draft is best. 

Have fun and don't worry about asking questions when you are stuck, there are a lot of very experienced people in the forum and between us we have tried most methods and can fix most problems.

All the best,
Charlotte