Lynnie,
The stuff at Michaels is called 'melt & pour' soap ("M&P") and is a very different beast from cold process soap! Melt & Pour is pre-made soap that you can simply melt down and then add stuff to. It's not all created equally either - personally I find the brands usually carried at craft stores to be very harsh. If you or anybody you are giving it to have sensitive skin, it's not going to be a good fit. On the other hand, you can make some very artistic and gorgeous soaps with M&P that are really really difficult (if not impossible) to make with cold process, and if you're willing to shop around and spend a little more you can buy some M&P bases that are better quality and easier on the skin. It's a lot easier to play with than cold process (especially if you're new to all of this) and is generally a better choice if kids are going to be participating because there's no lye involved; that part is already done for you.
Cold Process ("CP") is actually MAKING the soap - you start with raw ingredients (essentially; lye, water & fat/oil; plus whatever color/scent/etc.) and actually go through the chemical reaction (saponification) to convert those ingredients into soap. For this you need an accurate scale and you need to be careful; lye is dangerous if you don't handle it properly. If you measure wrong it won't turn into soap, so a good scale is really important, and you need to carefully follow your recipe. BUT...in my (not particularly humble) opinion, cold process soap is FAR superior to M&P soap as far as quality goes, and since you have 100% control over the ingredients you can do specific things - like my father had very sensitive skin so I was able to tailor-make a very gentle soap just for him. And you can still get very artistic with the soap, lots of fun ways to jazz it up.
If you've got a secret inner mad scientist that enjoys things like formulas and learning about fatty acid chains, CP soap is totally the hobby for you. I even bought myself a lab coat.
If you're more of a dabbler or just want to make some pretty soap that will smell good and look nice in the bathroom, go for the M&P. I did both! M&P is fun to make stuff for kids, you can do stuff like add plastic toys inside the soap. Can't do that with CP, the toy would melt!