With 500 days to go until the London 2012 Games, we present 10 things you need to know about buying the tickets which go on sale today.

1. Applications for Olympic Games tickets will be accepted between today and April 26, but there is no advantage to submitting an application on the first or last day.

2. This is only a request for tickets – for sessions where demand exceeds supply, a ballot will be held to decide on who gets what.

3. Payment will be taken from all successful applicants between May 10 and June 10, with people notified of any tickets they’ve been allocated by June 24.

4. Only residents of the UK or designated European countries can apply, otherwise people have to go through the National Olympic Committee.

5. The only card accepted for payment is a Visa Card, an official sponsor of the 2012 Olympics.

6. Customers are committed to purchase any tickets they are allocated through the application process, whether they receive all or only some of the tickets they applied for.

7. Once your application is processed you cannot cancel, change or return the tickets you are allocated.

8. Ticket preferences cannot be ranked so it’s worth taking your time in selecting the sports sessions and price categories you want. You can apply for a maximum of 20 sessions.

9. The opening ceremony is on July 27 and the closing ceremony on August 12. Ticket prices range from �20 to �2,012.

10. Tickets are arranged by category depending on how close you will be to the action. There are discounts for 200 sessions for under-16s and seniors.