There are 3 ways:
Go to the address: www.nextbuses.mobi
Go to your Mobile operator's homepage, select Travel and then click on NextBuses
Text 'Traveline' to 84268 and you will receive a reply with a link to the system that you can then save as a bookmark. This is a little more difficult to set up but it has the advantage that the service will be more personalised and you may also get better place searching.
A wide range of apps using Nextbuses data are available on Android, BlackBerry, iPhone and Windows.
Please contact Traveline if you find any of information on this website incorrect.