O*NET OnLine is an occupation database that allows people to search for jobs and careers by their own abilities, or see what kind of abilities are needed to perform certain jobs. This is a tool for people to find out the exact tasks and skills around a certain job. There are more advanced search tools for government employees (veterans, education, etc.) as well.
For example, Accountants career:
Develop, maintain, and analyze budgets, preparing periodic reports that compare budgeted costs to actual costs.
Prepare, examine, or analyze accounting records, financial statements, or other financial reports to assess accuracy, completeness, and conformance to reporting and procedural standards.
Review accounts for discrepancies and reconcile differences.
Prepare adjusting journal entries.
Establish tables of accounts and assign entries to proper accounts.
This is just a subset of the information provided on this career, which also has Technology Skills, Knowledge, Abilities, Work Activities, Education, Interests, Wages and other requirements and information.