Managing leads is a topic that always worth revisiting, because it's a place where things so often go wrong. I won't repeat the points in this great little MarketingProfs piece on the subject, but I'll call attention to one of their recommendations: "Know the sales process."
In most effective sales organizations, the sales force adheres to a standard set of practices that pertains to sales stages, training, forecasting, quota, bonuses, activity levels and how they pursue and generate leads.
A considerable amount of time is spent training and developing these sale processes, yet Marketing rarely has a firm grasp on how or why salespeople perform their duties. Yet, without that knowledge, how can marketers possibly expect Sales to take them (or their leads) seriously?
Ask yourself, when is the last time a member of your marketing team was seen in the "sales pit" or on sales calls? If you can't remember... it's been too long.
I've seen this part ignored so many times, but it's critical. If your processes for managing leads (particularly scoring them and handing them off to sales) aren't in sync with the sales team, things are not going to work. And while you may think that the way things are done in sales is not right, in most cases you're better off working with it first and then talking the your sales management about how you think it can be improved.
Otherwise, as happens all too often, you'll have a sales team complaining about "those worthless marketing leads" and become the handy scapegoat when somebody misses their quota.