Microsoft has recently released a document series which contain best practices for task sequences with Configuration Manager 2012 R2. This series goes trough a step-by-step in all the different steps in a task sequence.
For all IT-pros working with task sequences I suggest taking a look at the document series here –> http://www.microsoft.com/en-us/download/details.aspx?id=43412
In other related news, my fellow MVP Kent Agerlund has released a new book (updated) for Configuration Manager 2012 R2 master the fundamentals, which you also should take a look at if you want to learn more –> http://www.amazon.co.uk/System-Center-2012-Configuration-Manager/dp/9187445085/ref=sr_1_1?ie=UTF8&qid=1404503771&sr=8-1&keywords=kent+agerlund