Installing Components??

I havent installed that many components cause most everything I
want to do I can do through Delphi but I'm wanting to install some
of these nice components I hear about. I looked in the online help and thought
I was doing it right but I guess Im not cause half of all the components
I try to install give me errors like "one or more lines were too long and have
been truncated" , or I get an error like "File d:\.....\thiscomponent.pas
be found" but all I was given was the dcu file of that component.
Like I said, half of the time I get these errors, the other half I can install
component just fine. Its easiest when its already compiled as a bpl package
when I download it, I wish all component writers did it that way.
I've never had a problem when its already compiled.
What am I doing wrong?
Please E-mail me if ya can.