First off, congratulations on your engagement!
While I assume you've simply come across this randomly, just in case you're newly engaged and a bit lost on what to do now I have completed this short list to get you going.
Tell all your parents personally This one might sound obvious, but you'd be surprised by how many people simply post a status online announcing their engagement. While this is a great way to tell lots of people at once, your parents deserve to be told directly by yourselves. It could be a visit to their house, or simply a phone call to let them know. You will show them a lot of respect by doing this.
Set a budget You want a huge, Disney Royalty wedding with all the bells and whistles. £50k. Is that in your price range? I know, you've dreamt about this day for years. You want it to be perfect. But the best thing to do is be realistic. There are so many ways of building a perfect wedding day without going over budget. Take into account what you can afford, whether it's saving or within a credit you can pay back, and make your plans around this figure. You'll thank yourselves after the big day when you look at the invoices.
Make a guestlist Now, this doesn't have to be absolutely finalised straight away! It's just quite handy to decide whether you are having close friends and family, or going all out and inviting your great aunt twice removed. Having a general idea of the number of guests will help you stick to your budget, and decide on the venue. You can always invite more guests to the reception, and keep the ceremony small.
Pick a venue This one is important. The venue will be the focal point of the day, so you need somewhere you will adore. There are so many options and styles to choose from. Narrow your choices down, and plan it around your budget and number of guests.
Set a date Choosing the date is more difficult that you expect (see my post on how to choose your date), however once you nail it down then you're pretty much set! You will then know the when and the where; everything else can now be sorted! Just let everyone know to save the date.
BONUS:
Once you have chosen your photographer, book an engagement shoot pretty quickly while it is all still new and exciting. Your images can be used on your save-the-date cards for a more personal touch.