A few assorted links:
* If you are designing alien species or monsters, and want them to be realistic, you may find this website about different senses that animals have a good starting point.
* Stuck for names? The random name generator can help. It features several sets of names (American, Hispanic, Chinese, etc) and even generates addresses and other personal information! I would not personally use it for major characters, but it surely helps fill out the ranks of extras until you decide on better names, if ever.
* Charlie Jane Anders posted some thoughts on character design, which are probably not revolutionary but worth reading anyway.
* Tom Patterson is providing free, high quality shaded relief maps.