Hi - hope someone can help!

I'm not much of a gardener (or haven't been in the past due to my frankly tiny garden) but I'm just about to move into a bigger house and the lawn is a bit of a mess. I've got a young son and I'd like him to enjoy the garden in future so I'm thinking about laying a new lawn.

So... am I best off laying my lawn myself? I've seen a company (Rolawn) who sell turf online (http://www.rolawndirect.co.uk/) that one of my more gardening-centric friends tells me is pretty good. There's an online turf-laying guide there which makes it all look pretty easy, but am I letting myself in for loads of problems or should I just get a professional landscaper in (given my track record of killing things!)

Thanks in advance for any help and advice!