A verbal noun is a noun formed from a verb. In English this is done by adding an ending -ing to a verb and using it as any noun in a sentence. For example,
Singing is very difficult for me.
You need warm clothes for skiing in this weather.
In Finnish a verbal noun is formed by adding -minen to a 3rd person stem of a verb, like
laulaa > laula->laulaminen
hiihtää > hiihtä- > hiihtäminen