I've experience in designing the corporate identity and working with it. Now I'm the artworker in big pharma company but previously i worked in few Ad agencies and creating C.I. from time to time was my job :).
I should be simple, eye catching, it should have an explanation why it look like that, it should be adaptive to www, DTP printing and most important for your company - branding and outdoor.
I can help you with advise too.
So, Best regards
Łukasz Kozioł