Both WY and WL sell their yeasts and pitchable, and in most cases you can "get away" with pitching them in a beer under 1.060 or so. But you won't be making the best beer possible if you don;t pitch enough yeast. Fermentation is the key to making great beer. Making wort is only secondary.
Check this article here for more information: http://www.byo.com/component/resource/article/1749-yeast-pitching-rates-advance-homebrewing
As far as the best way to make a starter: you certainly don't need a stir plate. They do grow more yeast but they are not essential. I recommend getting a gallon glass jug. Use about 3 oz of DME per quart of starter. Boil the DME first, then cool before adding to your glass jug (unless you have a lab flask or some sort of thermal resistant glass jug adding it boiling will break).
Aerate well before adding your yeast and try and give it a good swirl every now and then until fermentation is complete. Then crash cool in the fridge for 24 hours or so, decant the spent starter beer and then pitch only the yeast slurry on the bottom. Check out the pitching calc at www.mrmalty.com
to get an idea how big a starter to make.
All that said, for new brewers dry yeast can actually be a better option. For one thing, dry yeast comes ready to go. No starter needed. Also, aeration is not as critical since all aeration does and build the sterols in the cell walls so that the yeast can bud. But dry yeast already has the sterols stored. The best dry yeast I have ever used is US-05. It is a very clean fermenter and attenuates nicely.