I am on the Ukulele Hunt mailing list and enjoy receiving their different regular newsletters, covering playing tips, articles, interesting books and sites, plus a selection of the latest on-line videos and recordings. The site itself has a wealth of information for all levels of players, so do check it out!
The webmaster, Alistair Wood, is also the author of the book Ukulele For Dummies (available in printed and electronic editions from the usual outlets), covering many of Ukulele Hunt’s topics in more detail. If anyone wants to view a copy, let me know and I’ll bring mine along to a future club night.
Some tutorial and reference items can be found on the For Dummies site – see their ukulele articles and ukulele videos. There are also singing tips for those who’d like to improve that aspect of their practice.
If you’re fairly new to learning the uke, I’d recommend you view the ‘Swiss Army’ ukulele strum, which is nice to learn to play, as it fits many songs.