sorry, but from a quick search here on the forums, and form reading threads, Yahoo is not the greatest host for your WordPress installation .. but now, if you like your site being up and down and up and down again .. they are great in those regards ...
i personally suggest you go with another host provider.
my local hosting provider is just right down the road from my house and they have fair prices and great support. never have experienced any down time and for the price, you cannot beat it ...
different markets support different prices for hosting and storage space, but for $50-$100 a year, they are not bad .. and they will even install the WordPress for you and help you out along the way ... really great guys.