Pre-coding planning

I'm an amateur programmer who has been studying .NET for the last 2 years off and on. I've finished a number of projects for family and at my workplace but they have all been relatively small.

I have plans to begin a project for myself that would definitely be the largest and most in depth that I have ever attempted. With all my previous smaller projects I have just jumped right in but with this one I feel like I need to do quite a bit of planning before I even write a line of code.

So, with that in mind, I'm looking for some links/books about planning for a project. Do I plan and work on my database structure first? Design the UI? Work on some classes? What general steps do you take when you first begin to plan a large project? I'm not even sure where to start.

Thanks for any and all comments and links!

My opinion only - others exist

What I'd suggest is get an A4 pad and a couple of different colour biros.
On each page (in colour 1) write the name of a THING that the system has to deal with
(e.g. CLIENT, INVOICE, ORDER, etc.)

For each thing make a list of the PROPERTIES of the thing you need to work with.

The under that list the ACTIONS or operations that can happen to that THING

Then at the bottom page list:-
What things are related to this thing
Do I need to store information about this thing

From this build your class library and database (if approrpiate)
Don't do the UI until last because it is the most fun part...

My opinion - no others exist

There's no point buying books about planning your next code session; that's like buying self-help books. You need to find your method of design and planning, then get started.

Thanks for the tips.