First of all, partitioning is a thing you really need basic knowlegde of partitioning and how it works. Otherwise you can screw up your drive.
Ok, now your questions/problems:
What is the total size of your disc? Is it 750152 MB?
borgward wrote:/dev/sda
/dev/sda1 ext3 / 14998MB
/dev/sda5 ext4 /home 735154MB
Why sda1 ext3? ext4 is much better than ext3.
Amount of space for the root partition is more than enough.
borgward wrote:I can not figure out how to make any more partitions. The only buttons active are change, revert, and delete. The add button is not active.
If your total disc size is +/- 750152 MB and you used the whole disc for the 2 partitions sda1 and sda5, then there's no space left. You can only add partitions when there's still room for it.
borgward wrote:What about swap?
You really don't need swap if you have over more than 4 gig of main memory. But if you really want swap, 1 gig is more than enough. So what you can do is resize sda5 and create a swap partition at the empty space.
borgward wrote:How to partition from the command line?
If you ask me, dangerous! Best is to use a GUI partition manager so you have a visual check on what you're doing. It is possible to use a command line partition manager but there's more room for making errors. Especially if you don't know what you're doing.
borgward wrote:Any thoughts about how I have the drive carved up?
This is a personal choice. I never create a separate partition for /home. Why? Because a lot of programs place their configuration files in the /home folder as a hidden file/folder. When you upgrade to a newer version and leave the /home partition as it is, you might end up with an installation which might be unstable due to the fact that you use old configuration files in a newer installation. Or you might end up with application errors due to conflicts between old configuration files and the latest/newest configuration file. So to avoid any problems i always erase my whole disc after i backed up everything ofcourse.