Creating/developing a brand startegy and plan

I have an exciting men's fashion related website project that I need some assistance with. I need some creative input and expertise in defining a brand strategy, some brand values, identifying a key target marget and developing a plan that can be used to underpin all the decisions that follow - mainly the design, content and marketing of a website. Having done a similar venture before - I now appreciate the need for some 'joined-up' thinking at the initial stage of development.