I am designing an DC to AC converter operating at 10MHz. Its a low power converter and the input current is under 2A. What PCB trace width should I use and can someone give me a guideline on how to select the PCB trace width based on the frequency.
At 10 MHz, you don't need to worry about trace width/impedance unless you're using long traces and very fast rise/fall times. At 2 amps I'd worry more about voltage drops. This calculator http://circuitcalculator.com/wordpress/2006/01/31/pcb-trace-width-calculator/ suggests 40 mil width if you want the trace temperature limited to 10 deg C. If you're happy with higher temps, of course, you can use a narrower trace.
If you are using very fast rise/fall times (regardless of frequency) and ringing is your problem, you'll need to use a trace impedance calculator, with the trace impedance matched to the load impedance.