most will have a go for free mate, get the details up and see what peeps produce.

Ideal info is:

Company name
strapline if there is one
type of business
type of target market
colours prefered

also, the use of the logo ie signs, vans, clothing, leaflets and letterheads, web etc etc (keeping in mind if it is going to be used large then it needs to be a vector so as to scale easily, or clothing may have implications on detail, and how many colours you want it.

Even if you dont get the finished article off here, if you get something close you can take to a designer, it will cut costs dramatically with a designer.