FAQ: How do I choose the right sequence settings?

In general, the settings of a sequence should match those of the primary footage type in the sequence. Though Premiere Pro can mix footage of various types in a sequence and compensate for differences in characteristics, performance and quality are maximized when such conversions are avoided.

 

See this video for more information:

How do I choose the right sequence settings?

 

Also see these sections in Premiere Pro Help:

Create a sequence

Sequence presets and settings

via Adobe Community : Popular Discussions – Adobe Premiere Forums http://forums.adobe.com/thread/878497