GBIF Data Portal - Access millions of data records shared via the GBIF network. Explore species, countries and datasets: http://data.gbif.org/welcome.htm
Taxonomy and online databases: http://www.eti.uva.nl/tools/links/taxonomy.php
World Biodiversity Database - The WBD currently consists of 21 separate projects, each with its own interface and feature set. These projects cover a total of 25493 unique taxa, plus an additional 4149 synonyms/ http://www.eti.uva.nl/tools/wbd.php
Additional links to databases:
Biodiversity and Biological Collections Software
Morphology and Imaging Hardware and Software
Phylogenetics Software
GBIF manuals: http://www.gbif.org/participation/training/resources/gbif-training-manuals/