#helst

adding gjerne to a sentence shows that you see something as desirable:

Jeg vil gjerne lære å gå på ski. I would like to learn how to ski.

It can also imply a friendly offer:

Du kan gjerne låne mine ski. You're welcome to borrow my skis.

Heller and helst are comparative and superlative forms of gjerne:

Jeg vil heller svømme enn gå på ski. I would rather go swimming than go skiing. Nei, jeg vil helst være hjemme. No, I'd prefer to be at home.

Gjerne can also be used to indicate what, as a rule, happens:

Snøen kommer gjerne i november her. Here, the snow usually comes in November.

Rather than expressing the 'desires' of snow, it is more similar to 'often' or 'usually.'