First Prepare the INDEX and Google it one by one and practice it, there is no shortcut to gain knowledge in single day.
coming to your point don't refer sample project at initial stages you may get confused. Once you get minimal knowledge about technology then start to read the existing project.
Useful topics
1) Create SharePoint site.
2) Web Application Creation
3) Sitecollection
4) Lists & Libraries
5) SharePoint WorkFlows.
6) WebParts
7) MasterPages
8) Site Definitions
9) CAML Queries
10) Publishing features
these are the topics commonly used while we are implement SharePoint project. Apart from the above we have several topics to implement but initial stages those are most important.