This is the start of a series of tutorials regarding the creation of InfoPath electronic forms. For the sake of simplicity and expandability in SharePoint, I will be limiting the form to a browser-based form (so that the form can be filled out using a browser like Firefox or Internet Explorer but this requires that you are running the Enterprise version of SharePoint and not the free version). Note some of the following limitations of using a browser-based form in SharePoint:
[EDIT: I've revised this information slightly on 2/25/2011 to better fit what I have learned over the past year...so if you read this before, it will have changed]
1. Performance - Browser forms means that another computer than your own must handle anything complex or difficult to calculate...this can result in a slower form than you might like. If you aren't using browser forms, then the form will open in InfoPath 2007 on your users' computer (if installed).
2. Security - You will want SharePoint to be running in an secure environment. How do you know if it's running in a secure environment? One way (but it's not always THE way) is to look at the very beginning of the web address for sharepoint in your company. If it starts with HTTPS instead of HTTP then you are good. If it is not, InfoPath transmits data as clear text in an xml file and thus can be intercepted. YOU are responsible for the security of the information in this form.
3. Difficulties with large lists - you will not want to use your form to connect and pull from a large list or library in SharePoint (or one that will be large any time soon...large being 4000+ items). In 2010, we will have the ability to just ask for specific information from SharePoint so this won't be a problem.
4. You must be willing to think and think logically to make a secure, fast form.
InfoPath 2007 and a well-rested mind.
Recommended: A SharePoint site in which you can create a Form Library (if you use a default configuration of SharePoint, you will probably need Full Control of a site or have the Site Owner create a Form Library for you to use and give you Full Control of it).
You can click below to go to the first step - planning out your form, menus, and layout tables - or use the links farther below for more information about InfoPath.
To get more information directly about InfoPath:
http://www.bizsupportonline.net/ - Site with topical tutorials on InfoPath 2003, 2007, and browser forms - includes code stuff
http://blogs.msdn.com/infopath/ - the blog of the team who actually design InfoPath
http://office.microsoft.com/en-us/infopath/FX100647031033.aspx - Microsoft's 'InfoPath: Help and How-To' site that usually has a bunch of quick articles and facts to help