As I covered in this post the Start menu is being reintroduced in Windows 10 and will include a side panel containing the live tiles previously used on the Start screen.
The image below shows the default layout of the Start menu when Windows is first installed:
To add a new tile to the Start menu, search for the item you want to add:
The right click on the item and select in to Start:
The newly added tile will be added to the end of the existing live tiles:
To move the live tile, simply left click and drag to the new location.
By right clicking on the tile, you’ll be given access to a context menu allowing the tile to be resized, removed or having gthe live aspect turned off. Further the pinned application can also be pinned to the taskbar or uninstalled: