yeah, websites arent just a form of advertising in themselves, but allow you to advertise yourselves in other ways then too. Such as links from online business directories. And they also work alongside any other advertising - as long as you promote your web address of course thereby allowing people to find out more about you and see your work.
If you get a website you need to make sure you have enough content for it to make it worthwhile though.
If people see your flyer for intance and go to your website and only see the exact same list of bullet points, and template picture, and no more, then theres not much point to it.
If you get a website makes sure people are immediately hit by your best quality work as soon as they pull up your website. Makes sure you have a portfolio of work with good pictures.
Although people can get to your website from hearing about you on the web, they are more likely to hear form you by word of mouth, business card, offline things in other words.. so make sure you web addess is on EVERYTHING if you get one. Your van, business card, adverts, flyers.... your website won't do much until you do all this other stuff straight afterwards.