Quick Reference Wedding Guide:

1. Buy Rings and Announce your engagement. Celebrate with an engagement party/photos (Optional). Send thank you notes for any engagement gifts received.

2. Arrange your Wedding Date and Venue for the Ceremony.

3. Discuss and set a budget and decide how expenses may be shared.

4. Agree on the level of formality and number of guests, colour scheme etc.,

5. Discuss any prenuptial agreement early on (Optional). Although these are not stricly binding in the UK.

6. Decide whether you are going to organise the wedding yourselves or hire a wedding consultant.

7. Select your bridal parties, on both sides.

8. List your guests.

9. Choose and book your reception site.

10. Hire a caterer, wedding cake etc.,

11. Discuss Bridal wear, and arrange fittings of bridal dress, headpiece and other accessories.

12. Order all Bridesmaids dresses, Suits and other apparel for your full bridal party.

13. Arrange transport for your bridal party.

14. Arrange a photographer or videographer.

15. Hire suitable entertainment for your reception. (Optional)

16. Organise a florist for your wedding flowers and bouquet.

17. Reserve a bridal suite and/or arrange honeymoon.

18. Rehearsal time is very important, for all involved.

19. Stag and Hen nights, (not the day before the wedding).

20. Relax, stay calm and enjoy it.

Don't forget : List

Be sure to find out about passports, photo identification and other documents required if you will be leaving the country.

Order invitations and thank you notes.

Arrange trial Hair/ Makeup appointments. To test out new styles.

Buy Gifts for the Bridal Party.

Double check : your marriage license requirements.

Send out Wedding Invitations at least 6 weeks in advance if possible.

Make any arrangements necessary for change of name and address.

If possible allow at least 3 months before your wedding day. 
Ideally, allow anywhere from 9 to 18 months.