Instead of "Where do I enter", I've been using F6 a lot more lately.  It's a keyboard shortcut to the forms list.

A few tips that I have to add:

• Spend some time going through the Options menu.  There's a lot of stuff in there for you to customize (like whether you want the date printed automatically, SSN masking, etc.)  These are going to be system-wide defaults so for the most part I just spend an hour or two at the beginning of tax season making sure everything is how I like it (including which forms print and in what order) and then ignore this for the rest of the year.
• Get very familiar with dozen or so sections of the Federal Information Worksheet.  This is where you'll find things like "Force Itemized Deductions".  It's also where you tell the software what states you're filing, where the refunds go, etc.
• As you enter tax return data, the "forms in use" section on the left side will populate and will also start creating red flags of things that the software really wants you to enter.
• One of my favorite tools is F8.  Client forgot to give me their car tax amount?  No problem.  I'll put $0 in for Sch A personal property taxes and press F8 to "Mark as estimated".  Then it shows up as a red flag and you'll be reminded in final review.
• That leads us to final review.  Use the Review button when you think you're done.  ProSeries will go through red flags, other diagnostics and then tell you all of the calculations that you have to verify by hand because they are "unsupported."

Rick