If you're new to Linux in general & Opensuse in particular this How to is for you.
Now the 1st thing to read this first:
SDB:Configuring graphics cards - openSUSE
However if you're impatient as I was when I started here's the How To.

This how to will have screenshots so you'll know what to expect. It is from my own experience at installation, so you 'll have a good idea of how it's done.
This is done in 3 parts.
When you need to bring up a terminal (Konsole in KDE Terminal in Gnome,xfce) it'll have this:
 CLI stuff here
DO NOT copy & paste directly from any code as your username won't be the same as mine, I'm robbie you very likely are not.

The How To:

This part is done while you're still in nouveau
1. Reboot your computer set it to nomodeset just like in this screenshot:

2. If you haven't already get the Nvidia drivers from here:
Drivers - Download NVIDIA Drivers
In this case we're getting the 256.35 drivers. Save it to Download, leave it there.
3.Open a terminal type in "su" without the quotes. As you type in your root password you'll see no dots after Password,this is a security feature not a problem.
The font will turn red after you've entered your password. Red for root get it? what you'll get will look like this:
robbie@dapc:~> su
Now to blacklist nouveau once you are in as root that's what this means "#" as root do not type # into terminal!, now type this:
 #  echo "blacklist nouveau" >> /etc/modprobe.d/50-blacklist.conf
press Enter close Terminal
4.Open Yast go to System then go to the /etc/sysconfig Editor find then click the plus on System to expand it then find then click the plus on Kernel it should look like this:

5.When you get there you'll see the value set to “no” just click on the no & delete it by backspacing
then type in yes just like in the picture click through the OK's.
6.With Yast still open Go to Software Management in the Search type then check to install the following: gcc
After you type kernel in search in the pane to the right check to install kernel-source,kernel-sym,kernel-desktop & kernel-desktop- devel
After step 7 this part is done on a black screen