I love wire! Sometimes I even take it out of the package to play with it. Truthfully it intimidated me at first. Then I got smarter and bought a DVD from wire sculpture.com and learned a great deal about what is possible with wire. I suggest you go to their site and look for the beginners series of DVDs. They cover tools,materials and have wonderful projects you can make in little time. Start with craft wire or copper or brass and practice. That's the key...follow the directions on the DVDs and make the rings or bracelets or stone settings in inexpensive materials a few times. Then buy some good wire and make a real fine piece.
These are the kind of labels you will encounter in wire...lets take one and dissect the secret codes..14G RD DS ARG looks like the secret squirrel code to open a walnut. but it really says the wire is 14 gauge round dead soft argentium silver. This is a tarnish free silver wire in a fairly large size. OK lets take another 22GHR HH GF its 22 gauge half round half hard gold filled. Its fine flat on one side and great for wrapping shanks made of square wire to both hold the shape and make it look nice. The Egyptian jewelers of old used this type of wire in the rings they made for the pharaohs.
The bottom one is 18G SQ DS GF 18 gauge square dead soft gold filled. The main thing to remember is the hardness,dead soft,half hard and full hard; each has a use...for intricately bent pieces use DS for shanks and prongs and general wrapping HH and for pins and very strong items full hard or spring hard. The sizes are obvious and if using beads match the size of the wire to the hole in the bead. The use determines what shape is best..round for casual,half round in small sizes for wrapping,in big sizes for shanks,and square for formal applications where multiple wires need to lie against each other.