Serendipity! I've just been buried in my seed catalog for Territorial Seed.  Yes, they have Ground Cherries which I've never tasted but am now intrigued.  Fair trade? here's a link to the Territorial Seed … please do tell what a Ground Cherry tastes like ……. the catalog says they are grown like a tomato and jammed like a fruit.  How interesting!

Lots of folks use the egg cartons.  I prefer to use the little bathroom paper cups & then I poke a hole in the bottom & plant the whole thing.  It decomposes just fine!

Be sure your seedlings have enough light!  Even a southfacing window may not be enough--a cheap fluorescent fixture with regular bulbs will do it--no need to buy the expensive grow light set ups.

Another thing that will make for hardier, healthier seedlings is a fan.  A fan will help keep mold and fungus from setting in, and the motion makes the plant stems stronger.  An oscillating fan is ideal, but any kind will help.

I am a Master Gardener--I took a class offered by Extension--and both of those suggestions came from our MG instructor.  If you have a chance, MG is an excellent program.

Google " extension, your state, your county" for the number of your local office and ask about MG.

Ross, lots of people are good gardeners, and that is an undisputed fact.  Master Gardeners exists so people can increase their knowledge of botany, soil science, plant propagation, landscaping, turf management, pest and disease identification and lots of other good stuff. 

Not only do you learn from the professors who teach the class, class members are encouraged to share their own hard won knowledge.

I took the classes, and for me, it was mostly a refresher of things I learned during my pursuit of a degree in Forestry and an MS in vocational ag.  I learned new things, too, of course, but it compared very favorably with college courses.

Of course, if you already know everything, you wouldn't need that kind of a class.