I don't really know about any of the PODs. Some of them sound great but, honestly, I'm not much of a digital guy at all. I work w/ computers all day so the last thing I ever want to see is another one in my guitar rig.
My best advice would be not to worry about any effects at all and find a guitar and amp (and maybe a distortion pedal) that sound great together and go from there. It's really easy to be distracted by effects, especially when you have twelve gazillion in one of those pedals. That said, there's a lot of cool stuff out there to be had but it's not necessarily cheap. It's a cliched bit of advice but all I can really tell you is to go to your favorite local music store and try out as much as they'll let you. I've found that I'm not a huge fan of the BOSS effects in general though there are a couple good ones (I like the Blues Driver). Some of the Electro-Harmonix are really cool but they tend to break (as do DOD and BOSS pedals).