Remove Features using PowerShell

http://get-spscripts.com/2011/06/removing-features-from-content-database.html

Diagnose Missing Web Parts

http://get-spscripts.com/2011/08/diagnose-missingwebpart-and.html

Overview of site navigation in SharePoint 2013

https://technet.microsoft.com/en-us/library/ee695757.aspx

Run site collection health checks in SharePoint 2013

https://technet.microsoft.com/en-us/library/jj219720.aspx

Branding issues that may occur when upgrading to SharePoint 2013

https://technet.microsoft.com/en-us/library/dn178510.aspx

Test and troubleshoot an upgrade to SharePoint 2013

https://technet.microsoft.com/en-us/library/ff382642.aspx

Upgrade databases from SharePoint 2010 to SharePoint 2013

https://technet.microsoft.com/en-us/library/cc303436.aspx

Introduction to the SharePoint Online Management Shell - See more at: https://www.itunity.com/article/intro-spo-management-shell-959#sthash.IHnAMznc.dpuf

https://www.itunity.com/article/intro-spo-management-shell-959

Gary LaPointe's Blog

http://blog.falchionconsulting.com/

Overview of the upgrade process to SharePoint 2013

https://technet.microsoft.com/en-us/library/cc262483.aspx

Upgrading from SharePoint 2010 to SharePoint 2013 Step by Step

http://blogs.msdn.com/b/alimaz/archive/2012/07/17/upgrading-from-sharepoint-2010-to-sharepoint-2013-step-by-step.aspx

Live Migration of SharePoint 2010 to SharePoint 2013

http://www.codeproject.com/Articles/663663/Live-Migration-of-SharePoint-to-SharePoint

SharePoint 2010 to SharePoint 2013 Migration Step by Step

http://www.falconitservices.com/support/KB/Lists/Posts/Post.aspx?ID=124

Upgrade to SharePoint 2013

https://technet.microsoft.com/en-us/library/cc303420.aspx