When I first started out learning 2 years ago, I got the book called "Ukulele method book 1" it is taught by Lil Rev, and put out by Hal Lennard.
I did learn alot about picking from it, and some about strumming, but as I got a little better, I got board with it, because it didn't have any Hawaiian ( local kine ) music. The majority of the stuff in it was nursurey rhyms, and songs that were popular from the late 1800's-1950's.
I would also suggest
www.tropicalstormhawaii.com
Also check out Aldrines lessons, quick tips, and Uke minutes, on this site, and on iamhawaii.com
Once you get better and want to start learning harder songs, also go check out Dom's site at dominator.ukeland.com ( I think that that is the right address ).
You can check out you tube too, but I found that when I was starting out, I just got frustrated by watching people do things that I wasn't ready to do yet. I would wait on that untill you have a little bit more skill.
But each player is unique, and what works for me, may not for you, so find what works for you and then play what kinda stuff you like.
Hope all of this stuff helps.
Aloha
Acabooe