How do I use aptitude

[Sean M McMahon]

I no the first thing one of you is going to say upon reading this subject 
line is read the documentation, but that's what I need to install and 
that's why I need some good help from you people.  I notice I have no 
output from which man so I thought I'd install man but when I look at 
aptitude I see an I next to some of the man packages does that mean their 
installed?  If they are, where are they and how do I set my path?  When I 
tried to install some documentation I saw a lot of packages with a P next 
to them what does that mean?  When I hit the plus key to mark a package 
for installation, the letter next to it said PI  what does that mean? 
Finally, what's the key command to show info about a package?  Sean