First off, this is a trouble-shooter forum, it is supposed to have threads with issues.  Don't use to as a measure of how complicated things can be.  Most people when they are happy, they don't come back until they have a problem.  Don't let it bring you down; there are plenty of smart folks on these forums to help others.
 
That said, there installation is a step-by-step process it isn't just plug and play.
 
When you first install the card, hook up the monitor to the card and power up the machine, you will see a smaller resolution than you had before and everything will seem slow.  This is because drivers haven't been installed yet, i.e. normal.  Be sure to toss the included CD in when the system starts.
 
In some machines with integrated video, you don't have to go into the BIOS an manually switch from integrated to using the PCIe slots, it should switch by itself (indicated by being able to see something on your monitor).
 
Anyway, either install drivers on the CD or downloaded from EVGA or nVidia.  Once you install drivers, restart the machine and fix your resolution to how it was before and enjoy.
 
Some folks will recommend a driver cleaning software, something to get rid of previous drivers to prevent interference with your new hardware.  You don't have to, but if you ever have to RMA your card and you default back on integrated video in the meantime, it is nice to have it as back-up instead of looking for those old drivers to get it working again.
 
Any functioning problems, just ask.
 
Performance problems are usually not functioning problems, they are just matters of perference and expectation; and yeah, ask about them too.

generally they are plug in, install drivers, play.
Problems normally arise from hardware/software incompatibility rather than an actual hardware problem.
These are problem solving forums, so if you do end up having a problem, there are people here to help.