Firstly, I suspect you are talking about US letter size paper. This is not "standard sized paper". It is only used in 2 countries in the entire world, the USA and Canada, despite Canada being otherwise metric.
Secondly you have 2 problems doing what you ask. Pages does not let you span "spreads" ie facing pages and you also need a method to impose the stapled booklet you are creating, something else Pages does not directly support.
To make text and pictures span 2 pages see where I have given detailed instructions to a recent earlier post.
To form your booklet up in the correct page order for printing you will need to do some nifty assemblage on a set of specially composed 2 page layouts or use 3rd party software to do it with exported pdfs. The process of assembling the pages in print order is called imposition. Look for software with this key word at
http://www.macupdate.com.au or
http://www.versiontracker.com.au
To make your own custom imposition you will need to lay out the pages in an imposed order, as below.
You did not say how many pages you wanted to put together in your booklet.
They are always in sets of 4 because there are always 2 facing you and 2 facing away on each sheet.
*For a set of 4 pages the order of pages is:*
1st sheet Front L4/R1 Back L2/R3
*For a set of 8 pages the order of pages is:*
1st sheet Front L8/R1 Back L2/R7
2nd sheet Front L6/R3 Back L4/R5.
*For a set of 12 pages the order of pages is:*
1st sheet Front L12/R1 Back L2/R11
2nd sheet Front L10/R3 Back L4/R9.
3rd sheet Front L8/R5 Back L6/R7.
*For a set of 16 pages the order of pages is:*
1st sheet Front L16/R1 Back L2/R15
2nd sheet Front L14/R3 Back L4/R13.
3rd sheet Front L12/R5 Back L6/R11.
4th sheet Front L10/R7 Back L8/R9.
*The pattern is always:* the sum of the two facing pages = all pages + 1.
On the front of each sheet you deduct 2 on the left & add 2 on the right, On the back you add 2 on the left & deduct 2 on the right.
Easier is to make up a "dummy" by folding up a piece of paper to form a little booklet, number the pages, tear up the folds then lay the pages out in order. Don't try to make up a booklet with more pages than will staple or fold easily.
This only applies if you are going to try and do this yourself. A commercial printer will handle all the details for you and do it more accurately than you can.