The single pilot of a VFR F-90 turned the wrong way after departure from TEB and overshot his cleared altitude.

Narrative

As I pulled up to the hold short line of Runway 24 there was a significant line of aircraft waiting to depart. After calling the Tower and asking for an ETD he gave me an approximately 20 minute wait. At that time I chose to cancel IFR and depart VFR to our destination. Approximately one minute later I was then cleared for take off; given a LEFT turn to the north east and an altitude of not above 1;400 FT. After take off I made a RIGHT turn to the north east. When I was about 3/4's [of the way] through my turn the Controller queried my turn and I was told I should have made a left turn but then cleared [me] to continue around and pass overhead the field; then turn to the LEFT to a north-easterly heading; which I did. While I was overhead the field I set the autopilot to altitude hold at 1;400 FT because my work load was rapidly increasing. Before I could notice the autopilot deviation it had climbed 100 FT to 1;500 MSL. At that time I corrected and descended back to 1;400 FT.I believe the reasons for this mistake are as follows. The clearance for the LEFT turn; the altitude; and the takeoff clearance were all given in the same radio call. While reading back the clearances I was also going through my flow of final before take off items. I was feeling rushed to get airborne to make the deadline the passengers had given me for their meetings at our destination. I was a single pilot flying in a busy airspace/airport.