The House of Commons, which is developing the guide, has begun the search for a direct agency to create the information pack.
Officials expect the guide to be completed by April and distributed from the middle of next year. It will then continue to be sent to teenagers as they turn 18. The government is aiming to mail out 600,000 guides a year.
The idea was among a number of suggestions put forward in 2004 by the House of Commons Modernisation Committee for improving political participation and boosting voter turn-out.
The committee recommended that the mailing should include a guide to registering to vote, a brief history of Parliament and information on the role of MPs, local councillors and other elected officials.
It has taken until now for the proposal to be approved and implemented.
The mailing will be sent out to 18-year-olds from all backgrounds, but the government is particularly keen to contact teenagers from hard-to-reach groups who feel alienated from the political process.
The agency search is being conducted through the COI. The House of Commons team is keen to install an agency as soon as possible, and it is understood that pitches will be held this week.