Eclipse
Eclipse has become one of the most popular IDEs not only for Java.
The C++ relevant tool plugin (CDT)
work very well. Eclipse is written in Java, which means
it takes a while to start up and consumes a signifant amount of RAM.
Apart from this little flaw, it is an excellent tool for your C++ project.
Eclipse can be used to organise your Project files (managed make). I personally
write my own makefiles, which Eclipse then uses without asking.
The biggest benefit, is the keyword completion functionality similar
to the IntelliSense feature in Microsoft Products.
I had some strange problems, when I wanted to use the Motif Version
of Eclipse/CDT, but GTK workes very well, so I use this one.