IMac :: Setup With SSD / HDD - Location Of Scratch / Home Folders?

What is Best setup for iMac with SSD and HDD? Best location of scratch & home folders?
Computer: iMac 2.93 GHz Quad core i7, 8GB RAM, 1 TB HDD + 256 GB SSD
There is not much info from Apple about the best way to set up an iMac with a Hard Drive and Solid state drive. I've looked at a few of the forum posts across the web and came up with a plan and lots of questions. (I do use photoshop frequently, but not on a professional level):

1.I will keep OS and Applications on SSD
2.Would you do it differently or not at all about moving the home folder? I saw some posts about moving the entire home folder, but it makes more sense to me to only move selected folders withing the home folder to take advantage of speed of SSD. So will keep the home folder on SSD, but move certain folders (document, music, iphoto, download, etc.) to 1 TB HDD via instructions I found on the macintoshperformanceguide website (**is this the same as creating an alias?):
cd
sudo cp -r Documents /Volumes/Master
sudo rm -rf Documents
sudo ln -s /Volumes/Master/Documents Documents
3.I will attach an external hard drive for most of my documents and backup storage
4.My main question and here is where I'm not sure what's best?

I want to speed up photoshop as much as possible? Should I make a partition on the internal HDD for a scartch disk? If so, how big? Is there a benefit to partitioning for scratch disc use? Should I not partition HDD and use for data and scratch? Any other way? I wish apple had a how to maximize use of the imac with HDD and SSD page!