Hmm....I don't know if crochet will felt. My gut says yes....but sacrifice a bit of yarn, do a swatch, and try it.
Here's a bunch of crochet socks patterns (FREE!) http://www.crochetpatterncentral.com/directory/socks.php
Now, again - I don't crochet, so I don't know how easy/hard it'll be. (For me, crochet is confusing - in knitting, all the stitches are neatly held on the needles - the left one is holding the ones that need to be worked, the right one has the ones already worked. Crochet...they just hang out. I can't tell which ones I need to work! :grin:
Yarn: Quality. That's a tough one, it really is! Some of it is personal - some people LOVE Noro sock yarns; I, personally, HATE it. It was full of short bits that poked out of the yarn proper, it felt like plastic...:ugh:
Basically, check to see how it's spun - are there lots of ends poking out of the yarn? Is it smooth, or lumpy-bumpy (and sometimes lumpy-bumpy costs more than smooth...go figure!)? Does it feel nice to you, or scratchy?
For socks (since you asked about them :grin:) I look for smooth, evenly-spun yarn, no lumps, no bits hanging out. I feel it - I like squishy socks, so I want the yarn to be soft. Then I look at color - does it appeal to me? THEN I look at price.....$18 isn't bad for Cherry Tree Hill - you can get "dealer's choice" from Simplysockyarn.com for $16.95 (they choose the colorway - you get what they feel like sending you). I haven't yet knit any up..but it feels nice, the colors are saturated and lovely....I'll try to knit a pair up in the next week or so and see how it does. For knitted socks you need about 300 yards for a pair of medium ladies (I know it works for my size 9s, so...:grin:) - crochet, I'm not sure. Lorna's Laces runs about $10.75/skein - and you need *2* for a pair of socks.
If you're not picky about colors or the patterns it makes on the finished socks, eBay is a good place to shop. JL Yarn's "Salvia" is a decent sock yarn - the colors are WEIRD, though (I feel like I have to warn people....I like bright socks; these guys are hit-and-miss), but $65/20 skeins is a GOOD price for sock yarn! (That's 10 pairs, with a bit left over out of each skein. Enough for a lacy cuff, I think) You can also score some "good" yarn for cheap, if you're not picky. (Noro for $13/ball, which made a pair. That's the Fugly socks I posted a week or so ago....again, *I* don't like Noro - but the price was good, and I was curious.)
KnitPicks.com has Palette yarns for $1.99/ball (or less). You'll need 2 for a pair...but still - $4/pair of socks. I don't know how it'd wear as socks (I'd use a size 1...I knit my hat on size 4s, for comparison)...and it's a wee bit itchy (but I haven't washed my hat, which could make a BIG difference). They have "actual" sock yarns for....$4.99/ball, I think - and I *think* it'd take 2 for a pair (brain-dead this AM). Their yarns are nice, though - terrific for the price!
JoAnn's carries Paton's Kroy Sock yarn (colors are.....different :lol:) and....don't remember the designer, but it's Serenity sock yarn. Prices are about $4.99 - $5.99/ball, but they're on sale right now (10% off) - they each take 2 balls/pair. Not bad yarns, prices aren't bad...the socks are a bit thin (knit them on the machine), but seem to be holding up to the kids' abuses really well.
Now, if want to talk "other" yarn (sweater/hat/blanket) let me know - I'm happy to blather on all day long. :grin: