Well welcome to the boards, and to the community as a whole. I'll add my two cents, for what it's worth.
First and foremost; read, read, read. Read the boards, you will learn a lot that way. Take what you've read and starting Googling around. You will pick up a lot of information that way. Secondly, head to the Live Music Archive at archive.org and listen to a bunch of shows using different rigs. You will start to quickly find what sound you like, what mics, etc.
When it comes to mics, if you are looking for small plug-in-power mics, like the Core Sounds, I would pass on those and lean towards either a pair of Audio-Technica AT853's or a pair of Naiant X-X's. darktrain (Robb) does a lot of work with Audio-Technica AT853's and you will find them in the Yard Sale regularly for pretty cheap. You can also score a new pair of Naiant X-X's for the same price from Jon at Naiant Studios.
If you want phantom-powered mics, like AKG's, Audix, Audio-Technica, Busman, etc., you'll likely find good deals on good equipment in the Yard Sale. There may even be a pair of Busman BSC1's in the Yard Sale now. You cannot beat those for a nice pair of first mics. Something along those lines would require either a mic-preamp (like a Naiant Tinybox, Edirol UA5, Denecke PS-2, etc.) and a deck (like the Tascam you mentioned, the Sony PCM-M10, or a Tascam DR-2D) or a deck with built-in phantom power support (Tascam DR-100mkII).
You can even find single, point-and-shoot microphones out there, for example, the Shure VP88 and the Audio-Technica AT822 and Audio-Technica AT8022.
The options are endless. I would suggest you monitor the Yard Sale for a while before making any decisions. You'll find this is a great community and a lot of tapers like to keep the gear in the community. You will, no doubt, find excellent gear at fair prices in the YS.
Hopefully that helps some.