the ultimate poi forums are on
www.homeofpoi.com (you can find me there too), they also sell everything you need to get yourself going, and they've got some great free tuition for the begginer. they are based downunder so if you'd prefere a more local supplier i would suggest
www.firetoys.co.uk they have quite a wide range, for begginning ire poi i suggest these
http://www.firetoys.co.uk/juggling/chai ... e_poi.html (the length is up to you, but i find longer ones are nicer for fire, and give less burns)
for practise (non-fire) poi then these are the bees knees of the seven seas
http://www.homeofpoi.com/shop/productDetails.php/268_45 (also available with glow balls, they're what i use when working in clubs)
if you have any questions regarding poi i'll be happy to answer them.
i've gotta go head out and try and teach someone to do a 5beat weave or a 4bt TTN or a 3bt BTB
(you'll soon learn what they all mean after you're on HoP)
edit: extra note, if you're going to order from HoP make an account with the forums and you get a 5% discount, or something like that