Depends on whether you want Catholic rosaries or another denomination. There are also chaplets which are smaller versions. They can be strung or wire wrapped, and can be used as jewelry or simply for prayer. I've made a number of rosaries and chaplets over the last couple of years for family members. It's incredibly rewarding.
www.rosaryworkshop.com is a great resource. The magazine Belle Armoire did an article on rosaries and chaplets in the winter of 2003. I don't know if the article can be found online, but perhaps the magazine issue can be ordered. There are lots of resources out there, you just have to do a little bit of work to find them.
Catholic rosaries are made up of decades. There are four sets of decades (10 "Ave" beads - I use 8mm for these) separated by 4 "Pater" beads (I use 10 mm for these). This would make up the large portion of the rosary. There is then a connector which is a Y shaped medallion. On the bottom part of the Y are 2 Pater beads with 3 Ave beads in between. At the bottom of this string is the cross or crucifix. The first one I made was for my mother's 60th birthday. I used 8mm round aquamarine Swarovski crystals for the Aves, vintage metal & rhinestone Swarovski 10 or 12 mm beads for the Paters. I found these beads in each of her 6 grandchildren's birthstone colors. I chose a SS fleur de lys for the connector and a SS Celtic cross for the cross. My mother is French and Irish. I then attached 4mm Swarovski bicones on headpins to the 2 sides of the connectors representing my husband & me, my brother & his wife, my father & mother & both of my grandmothers (they are wonderful friends and the only immediate family my parents have as both are only children with fathers not involved in their lives). This gift means the world to my mother.
The rosary I made for my grandmother was buried with her this past February.
A chaplet looks like a bracelet; it has one Pater bead with 10 Ave beads, with a cross/crucifix or other religious medallion attached. I made one for my grandmother for her 88th birthday with 8mm round amethyst (her birthstone)Swarovski crystals for the Ave beads, a beautiful amethyst glass lampworked lentil bead by Kim Watanabe for the Pater bead & a St. Therese medal. My grandmother's middle name is Theresa and my youngest daughter did research and took the name as her Confirmation name. My grandmother was quite touched.
I made a Salvation keychain for a friend who is a Christian a couple of years ago for her birthday. I used different shapes of 8mm Swarovski crystals in the 7 colors for the prayer beads & attached a SS prayer box to it. She loved it. I made it as a keychain because the only piece of jewelry she wears is her cross. She attached her key to her church to it.
Hope this helps!
One last thought - on the Pater beads the Lord's Prayer is said; on the Ave beads, the Hail Mary is said (at least in the Catholic faith). One more thought (cripe, this is my 3rd edit!) There is a book I have called (I think, I'll have to check) On a String and a Prayer. It's a wonderful book for making prayer jewelry.