Those are certainly some great comments that should help Confused. I might also point out that there are three different service levels to look for, based largely on size – but the over-riding value will come from finding a specialist in your industry. If there is such a specialist, talk to them first. Even if they’re not appropriate for you, they can probably point you towards others who are (we do that all the time).
If you can’t find a specialist, more general business brokers will handle smaller businesses, but tend to work more like real estate agents (sorry, guys), doing mass marketing and dealing reactively with inbound enquiries – size and scale can be useful here, to make sure you’re getting the right advertising, web listings, contracting advice, etc. Also like real estate, you should know that everything is negotiable, and the one watching out for your interests is you.
For somewhat larger businesses, corporate advisors can be more pro-active, and are likely to have more of a contact base to work with. They can also identify good and likely candidate buyers and reach out to them directly. This costs more and is generally specialised to the industry that the advisor has built and understanding of (and contact base in). If you are appropriate for this channel, the results are generally far better, too. (Declaring my self-interest, this is ICTSS, in the ICT industry).
For still larger businesses, larger advisory firms and investment bankers can help put together transactions. At this scale, it tends to be more about financial engineering than about the business, as there is either a small number of viable suitors (for a large trade sale) or a very large number (for a public float). If you’re at this level, they’ve already knocked on your door – these are not shy people.