1. An applications menu is at the top of the screen. Move your mouse to the top then press the right mouse button
2. AmigaOS/AROS has a concept of screens. Sort of like having multiple desktops but they can be spawned on the fly. Some applications like Lunapaint have a setting to "clone wanderer" or "use wanderer". This means to spawn a new screen or open on the main desktop screen.
3. You can see two screens at once by grabbing the screen title bar and pulling down with the mouse. You can flip between them with the gadget at the top right of the screen.
4. You can also flip between screens by using Left Windows - m. Left Windows -n always takes you back to the main screen
5. Every button on the interface can be configured and even the space between them. We used to call this MUI but apparently in AROS it's Zune.
6. There's a concept of having a working RAMDISK all the time in AmigaOS/AROS holding the running config. You can open it by double clicking the Ramdisk icon on the desktop. All dialog boxes have a USE button and a SAVE button. The USE button changes the running config and the SAVE button changes the config on the disk. I miss this. In Linux terms it would be like having /etc/ in ram.
7. There are three ways of interacting with an application - gui, commandline (AmigaDOS) and AREXX. I won't even begin to get into that here. Manual on AmigaDos. I'd forgotten how nice AmigaDos was.
8. AmigaDOS is a mix of many other commandline interfaces and doesn't take 100% from any. The wikipedia article on AmigaDOS is a pretty good overview and includes volume naming and some filesystem flag stuff.
9. AREXX is very very cool but I won't get into that now. In short it allows you to manipulate a program while it's running. This is an odd concept coming from other Operating Systems. If Linux were this way I could start the Gimp, then tell it via a script to go load a file, do some stuff to it and save it. This is a very very simple example. I used to have programs controlling and communicating with other programs. IBM owned REXX and a couple of years ago released it under the GPL license. I have fond memories of AREXX. Following is an example of AREXX code:

/* script to remove mods and demos from aminet recent files */
/* call it via rx de-mod.rexx input output */

parse upper arg input output .

if open('oldfile',input,'read') then do
    if open('newfile',output,'write') then do
        do while ~eof('oldfile')
            line=readln('oldfile')
            if pos('demo', line, 20)=20 then iterate
            if pos('smpl', line, 24)~=24 & pos('mod', line, 20)=20 then iterate
            writeln('newfile', line)
            end
    end
end
exit    

1. Fix the screenmode as I did in my Howto Install Icaros in VirtualBox
2. Run it in full screen mode
3. My first impression - it's ugly - it doesn't have to be, that's just Icaros theme
4. It's incredibly quick. You open a window and it just appears. I didn't realize I could see Linux drawing my windows until now. With Icaros you can't see the window being drawn it opens so fast. And this is in a Virtual environment with no graphic acceleration
5. It boots scary fast.
6. Open a web browser and type in google.com in the URL bar and wonder how it can load a webpage instantly
7. Some websites don't load at all - I think it's a javascript thing
8. I've been trained to work slow in Windows and Linux. Even the concept of copy and paste is slow. Directory Opus will show you this so spend a little time with it. It will feel foreign coming from the world of "Let's open two windows, browse to two locations, highlight files, copy them, then click on the other window and select paste". If you manage to get the hang of Directory Opus you'll be wondering why modern OSes suck so much.
9. It's sad this thing didn't last, it really is. I'd dedicate a bunch of time to the project but it's a lot like voting for an independent party for president.
10. Icaros is buggy. There's quite a lot of software that will lock it up. Also there are configuration variables that aren't filled. I tried changing themes and it complained.

1. Open Directory Opus from the task bar and get to know it. Left click to select, right click to go back a directory. Buttons have a right and left click as well. You can "click-m-click" too. This means click on a directory in the left window and very quickly click the right window. This directory will now be loaded in the right. Also making the Directory Opus window full screen will allow you to click on the left and right most areas which act as parent buttons.
2. Open Lunapaint and play around. If you haven't messed up your screen resolution like I have it's really nice to work with.
3. Play some demos, that will bring back memories.