There are 2 versions of the 2nd Generation Goldendoodle. The first is called an F1b and is simply the breeding of an F1 generation which is an English Golden Retreiver bred to a Poodle bred back again to the poodle. The percentages in this generation are 75% Poodle and 25% English Golden Retriever. Coat types can vary from Straighter/ Sporty to Loose Wavy/ Shaggy look to a Curlier, more poodle like coat. The 2nd version of the Second Generation would be the breeding of a first generation Goldendoodle to another first generation goldendoodle. This generation can create some interesting color options, F2 breedings can produce some unique color combinations and have the same percentages of poodle and Golden as the F1's. The Doodle in the Photo has a Loose Wavy Coat. He is an F1b.

Multigenerational Goldendoodles

Also called a  Muti-Gen Goldendoodle. This is a further down the line generation Goldendoodle that is produced from breeding the second generation back to a second generation or a First Generaton. 

An F3 Goldendoodle = F1B Goldendoodle X F1B Goldendoodle - 75% Poodle - 25% Golden Retriever

An F4 Goldendoodle = F2 Goldendoodle X F2 Goldendoodle - 50% Poodle - 50% Golden Retriever (shedding of this generation will usually be dependent on the amount of shedding of the parent dogs) The boy to the right has a gorgeous loose wavy coat. He is the product of 2 very low to non shedding parents that are F2 Goldendoodles.