When I opened the Photoshop program for the first time, I was completely lost. All I saw was a blank space with a tool strip (with weird icons!) and palettes that made no sense. Even if I COULD have figured out how to open a file, I wouldn't have known what to do with it!
I now know that there are pretty much two ways to get something to work with: (1) create a new image/workspace with File > New (or holding down "Ctrl" + "N"), or (2) open an existing image from your computer.
Here are my thoughts on opening (and closing) a file in Photoshop:
To open an image to work with, go to "File > Open" (Or "Ctrl" + "O"). This opens a file browser. (see picture at right.) Now you get to look for your file. Remember that you can change where you are looking for the file either through the drop down at the top where it says "Look in" (has a 1. next to it), or use the buttons down the left side (has a 2. next to it.)
This is why I think all your stuff should be in one place -- all your photos in one place (in sub-folders for organization, of course), all your digital scrapping elements in one place, etc. You don't want to be searching all over your desktop and hard drive to find the file you want to work with.
If you're not sure just where the file you have in mind is located (or you're not sure which kit to use with a photo), searching around through this "Open File" browser may not be your best bet. I always minimize Photoshop and look around in my actual file folders until I make a decision, THEN I go back to Photoshop to open the file. This way if you want to see a picture or element up close, you can double click on it to view it in Windows Viewer, then click through the other images in the folder. The only way to view a thumbnail file larger in the Open File browser is to just open it in Photoshop. (You can minimize Photoshop quickly by clicking on a "show desktop" icon (if you have one) on your Windows toolbar -- you know, that blue strip along the bottom of your computer screen next to the Start button -- or you can use the key combination "Window" and "D" to show desktop. ("Window" key is the one circled in red in picture above and at right.)
You can have several files open at the same time in Photoshop (you're not limited to one at a time.) (an example of how this looks is to the right.) If I'm working on a layout with a title or name using alpha elements, I'll open all the letters I need at the same time, to avoid having to open each one individually. (Although usually wherever you last opened a file from is the folder "Open File" will automatically go.) When I'm making a multiple photo layout, I open all the photos I think I may use at the same time. If having so much open on your screen feels too cluttered to you, you can minimize the photos/elements by clicking the blue box in the top right corner that just looks like it has an underscore symbol in it ("_") Doing this to photos causes them to line up at the bottom of the screen until you maximize them again. (See example at right.)
Closing a File
When you've been working on a file (like a picture or element) and have made changes to it, be careful not to save over the original file when closing. When you choose to close a file (either by clicking on the red X at the top right, choosing "File > Close," or using the keystroke shortcut "Ctrl" + "W"), a dialog box will ask you if you want to save the changes you've made. SAY NO! You don't want to save over an original! (Especially if you've drastically changed an element from a purchased kit -- most designers aren't going to e-mail you a replacement. There's no way they could keep up with everyone doing it if the option were open.) It's ok to use the --> arrow key to get "No" selected if you prefer keyboard shortcuts, but be careful -- once you've closed the file, the damage is done. And once you choose "yes" or "no" the file is closed. (If you panic at this choice or suddenly aren't sure, choose "cancel" so you can regroup.) ;o)