You might want to search this forum's archives.
Some specific answers/comments:
Calphalon is a brand of cookware, not a type. Their original stuff was anodized aluminum, which kinda looks like teflon, but is absolutely unrelated in any way, shape, or form to teflon. Now they make all manner of cookware. Stainless with heat disk, multi-ply stainless, the original stuff, and various subflavors.
Stainless cookware is fine as long as you don't overheat it. Also, the stuff with applied disks is prone to hot spots and sticking at the edge of the disk. If you really want stainless, multi-ply is the best way to go.
As for sets, they're fine as a starting point or if you're equipping your kitchen for the first time. If not, as others have said, consider buying the individual pieces you need, with an eye toward the right pot for the right job. Some good suggestions were already posted, above.
If you have a Home Goods or Marshall's by you, go there and look around. They have closeouts and overstocks and you can often find first rate stuff for way cheap.
Here's a link to a great site that has not only the cookware you might want, but a LOT of really, really good information. The link is to the site's page on cookware. Be sure to look all around the site, though. You'll get a good idea of what's out there.
http://fantes.com/cookware.htmI think if I were looking to have a basic assortment of 'starter' (or in your case, 'restarter') cookware, I'd go with a mid-grade line of multi-ply stainless.
I happened to be in K-Mart just this morning and, as is my habit, went to the cookware area. It seems that good ol' Martha Stewart has come out with a line of multi-ply cookware with copper exteriors. It is copper outside, aluminum in the core, and stainless on the inside. As a representative price, a 12" skillet with a helper handle was pretty reasonable (I thought) $29. The 8" skillet was $19. They had a few other pieces, too.
I have some older Martha Stewart triply (not copper) that really is pretty damned good. And we use our cookware pretty hard (but we also take good care of it, too). This stuff is now about 6 or 7 years old and has held up pretty well.
When you start to look at the truly dizzying array of options, consider what you'll be cooking and get the right tool for the job - right size for your family, right material for the job, right look and feel to meet both your aesthetic and functional sensibilities, and right price.
More money does not always translate into the best tool for the job. A $10 carbon steel European-made crepe pan will out cook the $120 All Clad crepe pan all day long and twice on Sunday.
The reverse is also true. A $100 tin-lined copper sauce pan will make a better bechamel sauce than a whole fleet of thin $10 Wal-Mart aluminum sauce pans.
Anyway, there have been books written on this topic, so all the answers you get here, collectively, only scratch the surface.
In addition to the link, above, you might also want to check out Alton Brown's "I'm Just Here For The Food". Or even better, his "Gear For Your Kitchen". Both have good, solid, practical (if a bit offbeat at times) information.
If, however, you have specific questions (rather than an open-ended one), I have no doubt you'll get a good answer here.
Bon chance! :hi: