SuSe will partition everything just fine. However you should be able to partition manually if you realy want. Probably by picking something similar to "advanced" install or something like that. Or more then likely SuSE will prompt you by saying something like "now we are going to partition your hardrive." and give you some options on what to do next, probably yes, no, or manually or something like that. Although I am not familiar with SuSE install so I can't be sure for sure.
Although the YaST installer is suppose to be the best installer out there in terms of OS installs.
If you are trying to dual boot it and have Windows on the same drive, you may want to to do it manually.. just to make sure... SuSE should be able to handle that automagicly and even set up the dual boot for sure. But it's better to be safe then sorry. Although if your going to try to do it manually then I'd do a bit of research on the naming convention Linux uses for IDE harddrives and partitions.
If you aren't doing anything weird like dual booting, then I say let the installer do it. It's the safe bet for a newb.
Good luck