Getting Started - what you NEED
Getting into this hobby can be a little daunting, let's strip it back and find out what you need to start this wonderful game.
The Rules
The basic rules can be found here. That has everything you need to get started with regards to character creation, game rules and magic. It's all free from Wizards of the Coast so don't worry about it. Character sheets are available to download from the website too.
An Adventure
Either come up with one yourself or use a premade one. There are free ones on the DMs Guild or you can use the official module books that can have dungeons in (Tales From the Yawning Portal) or a campaign book (Princes of the Apocalypse etc) which is a longer story.
Dice
The beginning of an obsession for some, dice collections can get out of hand! There are free apps and dice rolling tools online out there so you don't need to buy them. If you do buy them they are around £8 for a full polyhedral set, checkout your local games store or the dice shop online for deals and the type you want.
A Group and DM
Some people to play with. Get your friends or family around the table and have some RPG fun! If that is not an option then there are Looking For Group pages on facebook and you can try the bulletin board at your friendly Local Game Store.
A pencil
That is all you really need to play D&D. The other stuff I do on this site is nice but ancillary to what roleplaying is really all about. The Starter Set is a great way to start as well and at £13 you get an adventure, the basic rules, pre-made characters and a set of dice.
As a DM, once you have a group that want to play you can get the Core Books - Dungeon Master's Guide, Monster Manual and Player's Guide which have a more comprehensive rules and character options. The next steps are up to you but they are totally worth it!
May you roll well....