Finger Picking DONT CRY DADDY???

If you have the chords for the song, and know a few finger pick patterns, not really.  From that point it's giong to be practice, practice, practice to be able to finger the chords quickly and fit the patterns or make up new ones to fit the melody of the song. 

I would recommend practicing each chord change a lot of times until its mostly smooth, then start playing the song through with a very simple pattern until you can change the chords while playing the simple pattern.  Then start adding in singing.  And then practice adding in more complex patterns to suit your style.  It could take a while.  Don't be discouraged!  Take it as a "stretch goal" and continue to work on speeding up chord changes and making your fingerpick patterns smooth.  I can't tell you how many thousand times I worked on just two or three fingerpick patterns until my fingers do them automatically.  I'd sit there in front of the TV with my electric (unplugged) just going over them again and again and again.  Same with chord changes. 

It's all a matter of practice and staying enthusiastic now.

- Zurf