Your chip should be unlocked. Almost all t-birds over 1.2 (except for a few freaks) have their L1 bridges uncut, so no pencil trick needed there.
Check out Idaho's OC link to get the basics down.
You will most likely need better cooling to overclock with any kind of stability, but I don't know what you are running now.
I would just go ahead and start experimenting and see how it goes. You will know pretty quickly what speeds you can run at, and where your ceiling is under current conditions. I would check out the cases/cooling for an idea of what people are running to achieve similar OC's and gauge your system that way. Its pretty darn hard to kill your t-bird by over-clocking, b/c if you try running it at a speed it doesn't like, it just won't POST.
Biggest tip though: Make sure you actually have a heatsink attached and the fan is plugged in *ANY* time you turn your computer on. That seems like the biggest killer of t-birds, either no HSF, no fan, or bad contact between the HSF and CPU. T-birds get hot in about 5 seconds, so that little bit of time with no HSF is enough to kill it.
Chiz