Hi Edwin,
No doubt you have been reading the rather epic thread you started on the newsgroup.
I'm going to answer your question, but I think the better answer, to begin with, might be
"don't worry about the layout for now."
Now I know it's the natural thing to do - I've done it myself. I'm used to starting each procedure by getting the screen just right, then adding in all the code.
With NetTalk you will go faster if you think the other way around. With NetTalk you can throw controls onto a form or browse with literally no effort, and then get the program working. Along the way you'll change your mind about some things, throw some controls away, add others, perhaps abandon whole windows, or re-arrange work flow and so on. During this process you should simply ignore layout and visual style aspects.
Once the program "works" in the sense that all the fields and functionality are there, then you can start looking at the layout. At that point two things will happen. Firstly you'll discover that the layout can be set globally for the most part, so it's a lot less work. But also that you'll be a lot more familiar with the templates, so the layout settings will be a lot more obvious to you.
You'll still of course have some questions about how to do stuff along the way, but start with the practical stuff, and worry about the layout at the end.
Now to answer your question more specifically;
There are three kinds of "layout".
The first is all the cosmetic stuff. (And I mean "cosmetic" in the proper sense here - the important stuff that governs what it "looks" like.) You'll already have chose a theme for your app, but you can see the cosmetic stuff change just by changing the theme. (try Aristo, and ShoeStrap2 for examples of two very different themes.) This is probably the bit you worry about last, and the bit you'll want to tweak from time to time as fashions change. It's trivial to change the cosmetics globally - without even recompiling your app.
The second is the "form" of the app. For example is it page-based, or do you use popups? (Popups in the windows sense, not popups in the "web" sense of the word.) Or perhaps you're using a hybrid. Or with Content-body. again fortunately it's trivial to change this globally, so you can experiment a lot even after the app is built. I recommend setting everything up as-if it was popup based - then if you like you can turn it back to page based with a single global switch later on.
For example, if you are building a CMS, then popups are much faster when editing, but perhaps the user wants to see pages with the result. This is perfectly ok. (Generally speaking popups are a LOT faster for editing stuff than pages.)
The Third "layout" is controls on say a specific form. You want some on the right, some below, some spanning across and so on. This is done with the template options for each form control. Specifically;
Last on Line
Last in Cell and
Span Prompt/Value/Comment
Think of a form as a table, 3 columns wide. One column for the prompt, one for the value, one for the comment. (Actually you can make it a 2 column, or even 1 column layout, but let's stick with the 3 columns for starters.)
If last in Line is not ticked then a second set of 3 columns will appear to the right (with the next form field in those columns, on the same row.) You can go right like this as far as you like.
If the Last In Cell is not ticked then the next form field is placed into the same "Value Cell" as this field. This allows you to say put a checkbox and entry field right next to each other. In this situation the prompt and comment of the 2nd are usually (but don't have to be) blank.
You can play around with the layout if you like, but I recommend getting it all working before fiddling with layout. It's likely you'll make a lot of changes to things as you learn, and spending a lot of time on layout, only to abandon those fields later on is a waste of time.
cheers
Bruce