Knitters--a couple questions for you

I've been knitting for not quite 1 1/2 years, and still consider myself pretty new at it, so take my comments from that perspective. 

I use circular needles pretty much exclusively now. I have a vase full of straights, but I have a strong preference for circulars. You can buy them as interchangables or fixed circulars. Most posters on Ravelry will tell you to try some different needle brands and surfaces as fixed circulars first. That's probably a really good idea. I didn't quite do it that way. I'd only been knitting for a couple of months when I bought a set of interchangables-- the Denise set. A lot of knitters seem to turn their noses up at this set (the needles are plastic, and the cords are thick), but I think it's a great value for all that you get and a great set if you're just starting out. I still really like it. The nice thing about it is that you get needles in each of the most common sizes. You can make pretty much anything without having to shop for needles. 

At some point I ordered a sampler needle set from Knitter's Pride, and I learned that I really like wood needles (not bamboo). So now I have a set of wood interchangables, and a set of wood short-tip interchangables which I use to make hats. I'm not comfortable with metal needles at this point, but I'm open to trying them again in the future. I have a thing for needles. 
The ones I have are Knitter's Pride Dreamz. In the last few months I've learned to use Magic Loop to knit in the round for small circumferences, and you need the thin cords to be able to do that. That's a good reason to get a set like the Dreamz. But there are a lot of good brands out there. 

I do buy yarn that comes in hanks now. The first time I did that, I bought a skein that cost $30. Huge mistake-- I didn't know what I was doing, and I made a huge tangled mess of it when trying to wind it. I've gained experience and it's usually problem-free for me. I do not have a swift. I've considered getting one (still thinking about it), but at this point I seem to do OK without it. I hang my yarn over the backs of two chairs, or have one of my girls hold it for me. I do have a cheap winder that I got from Amazon, and it works pretty well. I think that most of them are the same, though I have heard that the one from Knit Picks has a covered mechanism, so you are in less danger of getting yarn stuck there (I've done that). 

Circullar needles can be used as straight needels so I find I would invest in them before straight needles. But, I inherited a whole bunch of needles from others so I have not needed to purchase very many.

Beware of the cheap bamboo ones - some are OK, but I have broke a few when making socks as the needles for that are very thin. It was so sad to have the needle break in the niddle of making a sock - had to tear out several rows to get it all straightened out.

Also, cause I use very sort circular needles for socks, I have had the plastic cord between the ends bread on me at the junction of needle and cord. So now I get the needles that have a bend in the metal part so my hand is not constantly pinching the cord against the needle part. AND the point at which the cable is attached really needs to be smooth so the stitches can slide over it easily. Its a pain when the joint between needle and cable keeps the stitches from sliding.

All this to say, you need to use a fiew circulare needles to figure out what works best for you. I will say this, when I splurged on a new set of needles from KnitPicks, I was really thrilled with them.

Are you buying at a local store or on-line?  If buying at a store, ask them to ball it up for you (some stores charge a small fee for this but it is worth it).  If buying on line, you don't NEED a winder.  I place the Hank over the back of a chair and manually make a ball myself.  However, if you had 10 hanks to do, then it would be worth it to invest in a winder/swift.

If you are going to try circular needles, whether fixed or interchangeable, be sure to get good quality.
Don't buy cheap ones, thinking they will do to try it out.  So often the cheap ones don't have a smooth between the needles and the cable and that makes the knitting hard work as you have to force the stitches over the join.  Good circular needles will have a nice smooth join that lets the stitches glide over.

If you want to try circular knitting, I would get a fixed circular in the size you need first.  That will give you an idea of what it's like to use them before you invest more heavily.

I knitted for more than 40 years on straights before I tried circulars - now I use them almost exclusively, for both circular and flat knitting.  I only use straights for yarn that is too fine for circulars.

A big benefit of interchangeable circular needles is that they make it so easy to have a couple of projects on the go at once, even if they use the same size needle.

You just unscrew the needles and screw on the keepers/minders doohickeys - knobs that screw onto the cable instead of the needles - then you just attach the needles to the cable with the other project and off you go.

I don't think knitting a shawl is harder than a sweater. There are a lot of great shawl patterns that are very doable for a new knitter. Check out trulymyrtle.com. Libby has a lot of shawl patterns that are not difficult to knit. She also has done some tutorials as well. She's from New Zealand and does podcasts that I love listening to.

Some people prefer interchangeables because it allows them to have just one set of needles and several cords of differing lengths. Some people like the permanent ones because they had problems with the interchangeables coming undone while knitting. 16" cords are usually good for some hats and cowls. There are some shorter ones. Longer cords are meant for scarves and shawls where you'd end up with 300 stitches in a row. Get some stitch markers for cowls and shawls. Don't buy the fancy ones just yet. Clover makes good basic markers as well as needles. I like them all - metal, bamboo, interchangeables and permanent circulars. I do not like plastic needles. I've had two break on me.

I also use double pointed needles for the majority of my in-the-round work.

As for winding, you can wind hanks without a swift. You either need a chair or someone who is willing to hold the hank so it doesn't tangle. You can also make a temporary swift with a small box, 4 plastic hangers, and some clothespins. I found the instructions on Pinterest under yarn swift. DIY swift If you do a search for it, a few other homemade options show up as well. My husband made me a wooden one. If you buy hanks in person at a LYS, most of them will wind them into cakes for you for free. Some might have a small fee of $1 per hank. If you buy them online through independent dyers, some will give you the option of having them wound into a cake before shipping. Either way, get a winder. I have this one: winder KnitPicks has one too for $20.