With the popularity of the new dual AMD platform, I'm sure that there'll be plenty of reading to keep you busy in the near future.
I have replied to several threads here and elsewhere, although I don't profess to be an expert, maybe somebody can bennefit from my experience.
Keep an eye out for threads from Dihard, Jon, SteenkyBastage and TC to name a few of the more knowledgable members in this regard.
You may also want to read this thread for some good information and a comparison of a couple of the currently hot boards;
AMD DUAL MOTHERBOARD SHOOTOUT
A little research will also uncover a new issue that has come to light in the last month or so. It seems that AMD has found a way to disable SMP on the XP CPU's by cutting an additional L5 bridge. There are several threads that deal with this as well as the fix necessary to restore SMP capability.
One other note worth metntioning is that the Tyan MP 2460 can be used with a standard ATX power supply, the only requirement is that there be 30A on the +5v line, whereas most of the other motherboards require a specific power supply for dual AMD motherboards.
A reply as I posted to an earlier thread;
I found the least expensive way for me to get into a new dual system was to take advantage of the "refurbished" section over at NewEgg. Keep an eye in there for the Tyan MP S2460. I picked one up for $129, combined with existing parts I had, I only needed an additional XP1600, and I went with 256MBs PC2100 Registered ECC RAM from Crucial (this ECC RAM may not be needed, from what I've read). I had to lay out about $350 and still had enough parts laying around to keep all of my exixting farm members crunching away.
Keep in mind that you can get good performance from the 1G and above Morgan's starting at about $40 each for the 1G. Although going this route may limit your FSB because of the defaut 100MHz FSB combined with a high multiplier and no multiplier adjustments available on this motherboard. This could limit your potential memory bandwidth.
Although limited as far as overclocking features on this board, you can get a pretty good boost from "CPUFSB" by increasing the FSB to 150MHz, this alone cut my SETI times from the high four to low five hour range per WU, to the low four to upper three hour range. This equals at least a 20% improvement.
My .02
Good Luck!