What's new in SharePoint 2013 for a Developer - quick Points

Design Manager
Snippet Gallery
Device Channels
Device Channel Panel control
Display template
Image renditions
Managed Navigation and EMM capabilities with Taxonomy
Content Search Web Part
Design packages
Catalogs
Cross-site publishing
Analytics and recommendations
Variations and multilingual sites

Change FARM Account Password in Central Admin Server

Login to Central Admin server and open SharePoint Management Shell as administrator.

Run the below command (Replace Credentials with your new Credentials of the farm)

stsadm -o updatefarmcredentials -userlogin sp\<Account Name>  -password <Account Password>

Have Fun :)