We just got Microsoft Office here a year ago. Plus if it is anything more than them entering in a name or pressing a button it might be a little too much. It seems like this project is going to be impossible to do because the end user is not going to have livecycle just adobe reader. I would have the IT guy at the site to setup the local databases for the users. The file would have to be posted to the intranet site where the extended right would have to be applied so the end user would be able to use it. It is basically like doing a Mail Merge in Microsoft Word. It only needs to pull the records that is associate with that one partical person. Your project is not impossible, it's just a steep uphill climb. The only way to reliably connect the form to a remote DB, for any user, on Windows or Mac, and from Reader or Acrobat, is through a server script that handles the data transactions. A Mac user will not be able to use a DB connected form. Also, it only works for users on Windows. This DB connection will not work (or work reliably) for random users on the internet. It is possible to connect the form to a remote DB, but the user will need to have the correct DB drivers installed on thier own system. By local, I mean a DB on the user's file system. However, XFA forms will only connect to a local DB from Acrobat, not Reader. If you want to create XFA forms you will need to learn about XFA form design and the XFA Scripting model. The only forms technology that can talk directly to a DB is XFA. But both form types are displayed and used in Acrobat and Reader. You create AcroForms in Acrobat and XFA forms in LiveCycle. So you have two forms technologies AcroForm and XFA.
To create an AcroForm you add form fields to a regular PDF using Acrobat Pro or Standard.
There is also a traditional AcroForm model. XFA forms are a relatively new technology. LiveCycle is only a design tool for creating the form. So the user's only needs Acrobat or Reader, they do not need LiveCycle to use these forms.
Both Acrobat and Adobe Reader know how to interact with XFA forms.
LiveCycle Designer is a tool for creating a special type of PDF form, called an XFA form (or XML form). The first thing you need is some perspective. Wow, you have got a few bumps to get over before you will be able implement anything close to what you are talking about doing.