Hello mate... its one of those things that its going to be really difficult to help without seeing it and turning the cranks
What i would suggest is reviewing a video like this
http://www.youtube.com/watch?v=Zt0ZZm3jTlMunderstanding what all the adjustments do on your bike and set it up as best you can yourself... if issues still remain then it may be due to wear of the components. Also just check for alignment stuff by looking yourself. from behind and above. Stuff should line up and be strait. If it isnt then its come loose and needs tightening, hasn't been put on strait, or is bent.
There is lots of stuff online. If you work out what everythign does then its easier to debug issues
http://bicycletutor.com/My fatherin law did these and thought they were good.. they are free after all
http://www.evanscycles.com/servicing/fr ... ce-classes