I am just getting started with some PICBasic projects. I haven't bought any of the hardware yet and have the following questions:

First, if I plan on putting a ICSP header on my breadboard, then do I really need to purchase a PIC programmer? It looks like the most basic ICSP programming interfaces are simply an RS232 level shifter? What's the most recommended?

Second, I am concerned about what the effects of the ICSP signals are to the rest of the circuitry. If you have your RB6 and RB7 pins connected to transistors, etc, then I assume you don't want the circuit to be triggering those components. The only thing I have found out there is that when you a resistor (10K or so) between the port and your component (which you would probably do, ANYWAY), then you are a little better protected? Is the convention to NOT power your circuit while programming? Do you have to include any kind of Diode to keep the ICSP circuit from powering the rest of your circuit during programming?

Thanks!
- Steve