installed new hard drive, won't recognize disc

You need to go to Utilities menu in the Mac OS X Installer application that boots from the Leopard CD. Open the Disk Utility application and use it to partition and format the drive.

Afterward, quit Disk Utility and continue with the Mac OS X Installer. Your new drive should now be available as a target for the installation.

It kind of depends on what you want to use the drive for other than just the operating system installation. If you're not experienced with partitioning, I would just set it to 1 and use all available space for the one partition.

Choose "Mac OS Extended (Journaled)" as the format. Also, click on options, and choose "GUID Partition Table". If you do decide to leave space on the drive instead of using the entire amount for the partition, you can create other partitions in that space later on from OS X, or even increase the partition size so that it sucks up the remaining space. So leaving space unallocated won't hurt you in the long run.

If you want to try playing around a bit, here's a bit more info.

First of all, remember that since this is a new drive with nothing on it, you aren't going to hurt anything by trying out different partitioning schemes and messing around a bit. You could always reformat the drive back to 1 partition and reinstall the OS.

Basically, each additional partition will appear as a separate volume in OS X's finder. So, conceivably, you could create multiple partitions and use them for storing different types of data or even installing other operating systems.

You can format each partition with whatever file system format you like. For instance, you could format a partition using FAT to make it accessible to both Windows and OS X.

You could create a separate partition using the same format as your OS X installation volume, then use it to clone your install using software like Carbon Copy Cloner. In case you accidentally screw something up royally, you could restore the backup to the main volume.

You could even set the clone as the boot volume and boot up your computer like it's a completely different machine using a different file system!

Hope this helps, and good luck!