Truthfully that guide is bad and I don't understand why they're using ps7. Ps7 has all the tools you need to do this but just for anyone else that reads this thread, Adobe offers cs2 for free so you get some new features.
https
/helpx.adobe.com/creative-suite/kb/cs2-product-downloads.html
To create transparency, you can just erase what you don't want and then just save as png. It's that simple unless you are talking about something else.
I could go into some more in depth steps though:
1.
Open the file: You can do, file> open, drag the image on the ps icon or into ps, or whatever other way to open the file in ps. When you open a jpg, it's a single locked layer. You can double click on the layer in the layers panel to unlock it. A new layer panel should come up and you can just hit ok. The new layer replaces the locked layer.
2.
Make the transparent parts: Just like opening, everything has multiple ways to get the same outcome but I won't go through them all. I'll mention 2 methods though. Use the eraser tool (E) to erase the part of the image you want transparent. (You can adjust the brush from the top or the brush window.) The other method is by using the lasso tool (L), magic wand (W), or other selection tools to make selections and then delete your selected area. (You can click the "refine edge" button at the top to adjust the edge of the selection which might be ugly.) Sometimes it's easier to select it rather than using the eraser. Whatever shows as the checkered squares is what's transparent. (There are multiple eraser tools as well as lassos. Any tool with a small triangle you can click and hold to bring up the other tools. Just wanted to mention this since ken mentioned the magnetic lasso and you just said lasso which is the default one.)
3.
Save the file: File> "save as" or "save for web." Both will work as long as it's saved as a png but save for web offers more options for better compression. It also gives a preview window. Png's do not save layers so flattening is not necessary. (Unless it's an animated png but that can't be selected unless you have animation set up. Fun fact; you can create animations in ps.) Hidden layers will not be shown when saved as a png so whatever you see on the canvas is what you get.
Pro tip:
The thing about deleting is that it would be gone forever which is why us pros use layer masks. This just makes parts "hidden" so you can just adjust the mask until it's how you want it without worrying that you will lose parts forever or not have to make copies and retry (or undo undo undo undo). Here's a random tut off google which seems to go into what I'm explaining. (I didn't read through it but it's from a reputable ps tut site.) Coincidentally he's using cs2 but as I said earlier, ps7 has all these tools. http
/www.photoshopessentials.com/basics/layers/layer-masks/
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