Ugh, I'm a total newbie and I know it

But I've kind of caught the fever here since buying my first house and now I want to build a workbench
I picked up a cheap, solid core door on craigslist to use as the top/surface
I cut off 6" to use as the backsplash
Now, I'm wondering what's the best/most solid way to attach the two together?
Glue and screws I would guess. But how exactly?
here's a pic of how it would be configured;

But I've kind of caught the fever here since buying my first house and now I want to build a workbench
I picked up a cheap, solid core door on craigslist to use as the top/surface
I cut off 6" to use as the backsplash
Now, I'm wondering what's the best/most solid way to attach the two together?
Glue and screws I would guess. But how exactly?
here's a pic of how it would be configured;
