Useful links:

Kinbase, a resource on protein kinase gene
Protein Kinase Resource, a compendium of information on the protein kinase family
Kinase Sequence Database, a collection of protein kinase sequences
Kinase Pathway Database, a database of pathway graph image and protein protein interaction
RTKdb, a database of receptor tyrosine kinase
PhosphoBase, a database of phosphorylation sites
PlantsP, a database of plant phosphorylation