Keyword Resources
Due to the importance of keywords in relation to online business success by attracting qualified visitors there are a number of useful services online.
Wordtracker
This service lets you search their 300+ million query database on your chosen keywords for alternative keywords. This can be very helpful to for building long lists of related keywords.
Wordtracker is a top quality subscription service, which also offers a free trial restricted service.
Jimtools
Have some very useful keyword resources, along with other online tools.
Jimtools Keyword research tool suggests related keywords from your keywords and you can select form a number of search engines.