A little technical experience is required, but I create my forms at
http://www.tele-pro.co.uk/scripts/contact%5Fform/. After you do it once, there's a pretty fast learning curve. You can choose whatever fields you want people to enter and whether or not they are required. There is not limit to the amount of fields you can use. Best of all, it's free to use.
One thing to keep in mind though: the more fields you require people to fill out, the lower the probability will be of people filling out your form. At the same time though, those who do fill out your form will be higher quality prospects.