You might want to look at using a scripting language such as php or perl. For storage you might also want to think about using a database such as Mysql.
You're right the form will usualy be plain html, you can then use php to process the form and save the information within a database.
How this will be done depends on a number of things such as what information will you gather, who will be able to see the data and how will it be stored, for example do you want every users data shown as one survey, or do you want to compile the data?
I have MySQL Databases set up on my site and use some php in the forums. I would like to gather the data per user, rather than compiled. And this data will be viewed by the management staff to determine what course of action they will take.
My client has a customer base of around 350, and they are trying to get feedback sent back to them on certain fields of information, so I am trying to get a form set up that will gather the data.
I really appreciate any help, I am about half way to understanding this, and I think with a bit of help, I can get this to function.