I see you have asked this question in several different ways in different forums, including SHOUTING your question in at least one post. So, I'll give you the answer you seem to want:
*Get a copy of Windows, install it on your Mac using Bootcamp, and viola, you will now have access to the Tile and Cascade functions by right-clicking in the toolbar*.
Seriously, Mac OS X is not Windows, and vice versa. +There is no Mac equivalent to the Windows 'Tile Windows' command.+
So, you can teach yourself to use an alternatives like Exposé. Alternatively, you can use ⌘-Tab to cycle between apps, similar to Alt-Tab in Windows. One difference there is that in Windows Alt-Tab cycles through all open windows of all apps (e.g. if you have three word docs open, Alt-Tab will cycle through them all), whereas ⌘-Tab on the Mac will cycle through apps, but not docs within apps (so, in the above example there's just Word, not 3 Word docs). On the Mac, ⌘-` (the key just above Tab) cycles through open windows within an application. Personally, I usually have several apps with several docs in each open at one time, and I find the combination of ⌘-Tab and ⌘-` quite efficient for moving through them.
Or follow my first (facetious) suggestion about installing Windows.
Hope this helps...