The internet is a big data base, it contains a lot of useful information. It also provides useful tools. Here are the sources that I recommand (they may not be related to night photography)
Dchome is a Hong Kong photography forum. There people posting useful information and their work, some of them are very impressing.
http://www.youtube.com/user/PhotoGavin
This is Youtube channel created by a person called Gavin. In this channel, he uploads videos about using Photoshop, shooting pictures outdoors. It is a great Youtube channel.
http://www.youtube.com/user/DigitalRevCom?feature=g-all
This Youtube channel is mostly reviews of photography equipment, the reviews are quite updated
This is a free online photo album, it has no limitations on the amount of photos you upload, but there are not too many people using it compared to flickr and other popular online photo album.
http://www.startrails.de/html/software.html
This is a free software to stack startrails image. It is simple and easy to use, I highly recommend it.
This is a website with detailed lens reviews, photographic equipment news and other useful resources