Week 4 Muddiest Point(s)

I have two muddiest points this week:

First, I went to the Unicode web page, but I don’t understand it.  Is there a program (is it this version 5.2.0?) to download that gives you access to all the languages/fonts?  Or do you simply locate a particular character you want and copy and paste it from the charts?  It all looks very complicated.  I often need access to Arabic and Chinese characters--is this what I should be using?  I understand Office 2007 has a full symbols library that has what I need, but I don’t have Office 2007 on my computer (I could get it--I just can’t make the time for the transition at the moment).  So in a nutshell:  how do you access Unicode characters, and where do they go once you access them, and then what do you do with them? 

Second, at what point do you choose a compression file format?  Do you always have the option of saving an image as a TIFF, a JPEG, or a PNG?  Where do you get those options?  I don’t recall ever having any choice.  When I download images from my camera, they are automatically saved as JPEGs.