What you need:
4mm Jump Rings (made using 0.8mm wire) I have used Silver Plated here and you can see how to make them by clicking here.
A Piece of Scrap Wire This gives you something to grip while you get the first few rings worked.
A Toggle Clasp Any closure will do but I prefer toggles.
Two Pairs of Flat Nosed Pliers I use a long and a short just because its what I have and am now used to but any will do as long as they are smooth so as not to mark the metal.
1: Secure the scrap of wire through two closed jump rings.
2: Now add two sets of two jump rings so it looks like this.
3: Holding onto the loops and wire fold down the top two jump rings and open the two apart that are now at the top.
4: Open a new jump ring and capture the two rings that you had folded down and pull them up.
5: Now do this again with a second ring and you can see you pattern starting to form.
6: You now need to add two sets of two jump rings again like you did at the start.
7: Again fold the top two jump rings down and and split the next two apart.
8: Using an open jump ring capture the two folded down jump rings and pull them up.
9: And do this again with a second jump ring. You now have your pattern. Just follow the same steps over and over until you have your desired lenght for your bracelet or necklace. Simply attach your toggle clasp using jump rings and your done!