Select the "Add" button. Define the swap area first-don't specify a mount point, specify the Size in MB, and select Type: Linux Swap. Select "Ok".
Select the "Add" button. Specify the mount point (ie. /, /usr, /data), and size in MB, select Growable if you want to let Disk Druid tweak your settings, and select "Ok". Repeat for each partition you need to add.
If you are keeping other partitions that you want Linux to be able to access, specify mount points (ie, /dos/c, /dos/d, /winnt/e) for them using the "Edit" button.
Select the "Ok" button to activate your changes. Answer "Yes" if you are sure you want to accept your changes, "No" otherwise.