Google-forms – How to add attachment option in Google Form

There are different ways you can view a document made in Google Apps

1. docs.google.com/spreadsheet/pub
2. docs.google.com/a/domain.com/spreadsheet/viewform?formkey=FORMID
3. docs.google.com/spreadsheet/viewform?formkey=FORMID
4. Embed on domain of application

Where 2 redirects to 3. Option 1 is most likely what you want users to see.

Option 1 is found via File > Publish to Web. Here you should see the choice to let users sign in with their domain.com account. This is greyed out but we will deal with this a little later on Thus if I am no signed with a domain.com I will get the request page. You will need to go to Form > Edit Form and change the sign-in option to view the form (not the spreadsheet). Now depending on your visibility settings you may get a pop-up asking whether the form should be seen outside of domain.com.

If you wanted Option 4, don't deselect this option. You will need to get this on the domain itself so for example domain.com/form.html. Using a Google sites for example https://sites.google.com/a/domain.com/test/ to handle the form will not work.

If you selected the uncheck the sign-in to view form, Option 3 should now work.

To get Option 1 working the admin of the Apps account needs to go in the Dashboard settings and manually enable it. Note changes will take a while to propagate, be patient with this change in the dashboard

I only seem to have some bad news for you.

1. It is not possible to customize Google Docs Forms in another way than using the provided themes. (See Google employee AnaLikesLattes' answer)
2. It is not possible to enforce one-submission-per-person but you could maybe use required fields asking for first/last name or email. (Google Docs Help discussion)

I'm not sure about SurveyMonkey (haven't used it) but for more advanced surveys I'd suggest using SurveyGizmo. They offer a free account with 250 responses per month. Comparison of their plan features here.