What is the best contract management, lead/sales management, time sheets, and invoicing software for a small management consulting firm?

As far as lead/sales management goes, you should definitely look at http://www.bizconnector.com. With sophisticated email marketing automation capabilities, it automates many lead nurturing and customer retention functions that can keep you focused on delivering value to your customers. As a management consultant, your biggest bottleneck is your own time (I know...I was one!), and you don't want to be spending time segmenting your customer base and sending emails out to cold leads who will only become customers 8 months from now.

You can have a look on FormGet, an online form building and lead management tool. You can collect all your lead data at one place and manage all your leads data without any hodge-podge. Besides, you can have a quick 2-way communication (client- support member) right from the single platform. In a way, you can help your clients quickly to solve out their issues. Educate your client about your product and many more. Have a look on the application to the link give below: http://www.formget.com/

As a BlueCamroo user, I'd endorse Karl's comment. If you're billing time, the timers and timesheet handling are unbeatable.  I particularly like the way it's one click to get a billing schedule all properly calculated through with each consultant's billing grade, and also that I can then adjust this by overriding the billing grades for certain components of the job.  That's huge time-saver.