The pilot scheme will be launched at Nationwide and Ford which have worked with Macmillan on an expert panel to provide information and evidence on current practices and issues within the workplace.
According to Macmillan, 90,000 people of working age will be diagnosed with cancer in the UK this year but many lack the support and advice needed to remain in or return to work.
The charity claims working is important to people affected by cancer because it can help regain a sense of normality after the diagnosis. Macmillan's research has also revealed that 68% of line managers need more information and guidance on cancer.
The toolkit contains information for employees and managers including: how cancer affects people; how to speak to people affected by cancer; workplace support strategies; personal finances; and legislation.
The pilot will run for nine months to test the delivery and impact of the materials that have been produced, with a view to launching them to businesses and organisations across the UK from summer 2010.
Mike Hobday, head of campaigns and policy at Macmillan Cancer Support, said: "Employers play a pivotal role in supporting people with cancer and a good relationship is most likely to lead to a successful return to work, which is in the interests of both parties."
Cancer is covered by the Disability Discrimination Act, which means employers are legally obliged to make reasonable adjustments for employees that are affected.