here is the way i do it, and often.
open the MB box inside the wrapper is a piece of foam take it out put the MB on to it, then fit the CPU and the RAM and the heatsink and fan... connecting the HSF power lead to header1 on the MB.
next fit the motherboard riser screws to the case taking out the backplane if possible, next fit the motherboard screwing it into place, oh before fitting the MB just put it inside the case and make sure all the ports on the motherboard can be pushed throught the case if not remove the blanking plates that are in the way from the case...assuming you are using ATX parts.
next put the PSU power connector to the MB, then fit the Video card only.. locate the soft swich lead from the case fit it to the motherboard.. power switch or on off swich it m,aybe called....next conncet monitor and switch power on, monitor first then computer. if all is well the screen should show the cpu speed and test the ram - thus showing that these parts you have installed are working and its ok to finish building the computer. So now add hdd, floppy, cdroms etc until you have installed all the parts. if all looks well then proceed to fdisk the new hdd and format it.... a quick note if the floppy fails then rotate the floppy ide type cable 18i0 degrees and refit but do this only on the floppy not the MB ....
next install OS of your choice but if its going to be windows 2000 then best to boot from the cd. best of all read the motherboard manual it tells you heaps about things in the bios you may need to alter for what ever reason you might want to "overclocking and stuff"
well thats all folks hope this helps