My website brings in loads of work. 
I'm fussy though,.. i prob only accept 1 job in 4.
Is the work local to your business or do you recieve calls from all over the place?Thanks for the answer by the way.
I do get some calls/e-mails for jobs out of my area which I pass on to guys closer to hand which suits me fine as they pass on work to me also. I also get calls for national contracts which I'm simply not able to consider being a one man band,.. so again I pass these on to someone who is more able to manage them. The rest (prob half of all that contact me) are local and within my abilities and I get approx half the jobs I quote for. To date I have approx €1100 per month of mainly commercial work that I know came direct through my website.
Its important to design & optimise your site to work with Google, and get your keywords spot on, otherwise you won't see nearly the results you should.
Just in case you peek at my website,.. I know its a bit dated, I'm planning a complete overhaul in a couple of months with 2 separate sites, one aimed at commercial clients & one aimed at gaining residential work.
Mine brings in nothing doesn't even get any hits :
What's your website address? I might be able to help