Targeting basics

Question

First let me appologize for what will seem a very basic question, but I am new to InDesign and Scripting and just had this project laid on me, and I can't seem to get my head around it.
Lets say I have 4 pages in a document.
Page 1 has 1 textframe
Page 2 has 2 textframes
Page 3 has 3 text frames
Page 4 has 4 text frames
Does using myInDesign.Documents.Item(1) target a page, a document, or a textframe?
Does using myInDesign.Pages.Item(1) target a page, or a textframe?
How do I target Page 2?
How do I target Textframe 3 on page 4?
Next, how do I target XML Nodes.  For example using the example XML from Adobe I have something like this:
<code>
<devices>
          <device>
                    <name>Pulse/Triangle Voltage Controlled Oscillator</name>
                    <type>VCO</type>
                    <part_number>DS001</part_number>
                    <supply_voltage>
                              <minimum>3</minimum>
                              <maximum>18</maximum>
                    </supply_voltage>
                    <package>
                              <type>DIP</type>
                              <pins>16</pins>
                    </package>
                    <price>3.25</price>
                    <description>A wide range, temperature-compensated voltage controlled ocsillator featuring 1 volt per octave exponential response. Pulse and triangle waveform output.</description>
          </device>
          <device>
                    <name>MultiWave Voltage Controlled Oscillator</name>
                    <type>VCO</type>
                    <part_number>DS002</part_number>
                    <supply_voltage>
                              <minimum>3</minimum>
                              <maximum>15</maximum>
                    </supply_voltage>
                    <package>
                              <type>SOIC</type>
                              <pins>18</pins>
                    </package>
                    <package>
                              <type>DIP</type>
                              <pins>18</pins>
                    </package>
                    <price>3.79</price>
                    <description>A wide range, temperature-compensated voltage controlled ocsillator featuring 1 volt per octave exponential response. Pulse, triangle, and sine waveform output.</description>
          </device>
</devices>
</code>
If I target myDocument.XMLElements.Item(1) I all the data in all the nodes, but if I try this: myDocument.XMLElements.Item(2) I get an error saying it doesn't exist.
So my question is, what is the best way to get the value of a node in the tree, for instance "<part_number>"?
thanks in advance

Answer 1

Jongware - that was extremly helpful and exactly what I needed for the XML.  I was able to write out nodes in newly created pages and textframes, so thank you very much.
Would it be possible to also give me a few examples for my first question, regarding pages and text frames.  If it is similar to the XML I am assuming it would be something like this...
myInDesign.Pages.Item(1).TextFrame.Item(1) - target first frame created on first page
myInDesign.Pages.Item(1).TextFrame.Item(2) - target second frame created on first page
myInDesign.Pages.Item(2).TextFrame.Item(1) - target first frame created on second page
If the above is not correct, then I guess i am still not clear of what "Item" is refering to. So to go back to my original post...
Does "Item" in myInDesign.Documents.Item(1) refer to a page in the document, or the document itself?
Does "Item" myInDesign.Pages.Item(1)  refer to a page, or a textframe on the page?
Thanks again
Update: ok I think I answered this after playing around with things today.  So I think the short answer is that ITEM refers to whatever preceeds it, so myInDesign.Pages.Item(1) refers to pages, and TextFrame.Item(1) refers to textframes.
I still have to figure out how it orders things though.  I tried creating two frames on a page then replacing the content in the second one I created with TextFrames.Item(2), but it replace the content in the first one I created instead.