Lily bulbs

This my first year of growing lilies, not a great fan personally but the OH likes them. My question is, do they multiply or are the bulbs sterile?

I have no idea of the type as it was a mixed 8 pack from Wilko's.

Also does anyone have a recomendation of any varieties?

Lilies I have grown in the past do multiply when they have died off leave the stems there for a few weeks then later look at the bulbs and you will see small bulbettes