Newbie Owner - Need advice

[prhood]

I'm in a 5v5 Roto league for beginners.

After much player movement I've settled on the following roster:

C - Chris Shelton
C - Greg Zaun
1st - D. Lee
2nd- J. Kent
SS - M. Tejada
3rd- R. Freel
OF - J. bay
OF - G. Sheffield
OF - M. Cabrera
OF - M. Holliday
OF - N. Swisher
U - J. Giambi
U - D. Johnson
P - E. Bedard
P - M. Buehrle
P - D. Willis
P - T. Hudson
P - N. Lowry
P - D. Wells
P - M. Clement (Res)
P - H. Street
P - D. Turnbow
P - B. Wagner
U - M. Sweeney (Res)

Should I be looking to move/trade some players and if so whom.

I'm in 4th place in a 10 team league but 20 pts behind the leader.