There are good video tutorials at the following sites.

Geekatplay = www.geekatplay.com
They are free to view online or can be purchased at reasonable prices.

Youtube = www.youtube.com
In youtube search engine just type in "Daz Studio".

Maruut Software Training = www.softwaretrainingtutorials.com
These are professional quality and as such $$Expensive :-(
(my company purchased the AutoCAD video so this is how I know about this site).

Also check out Daz's own tutorial section = www.daz3d.com/i/tutorial/0?_m=d
This is were I started to learn at the magic 4 letter price tag $FREE ^.^