No matter what I do I usually end up getting beads everywhere, lol. I also usually have to buy more threads, particularly metallic ones.
There are two ways you can attach the bead. You use a single thread. Bring your needle through as though you were going to do a half stitch but before you complete the stitch you attach the bead. This means the bead is sitting on a slant which can look nice. If you want it more secure you come back through again as though you are finishing a cross stitch. Bring the thread back through the bead and then come back down to finish the cross stitch. This makes the bead straight whcih is just as nice. I would recommend that unless the chart tells you to do so you do it one way or the other.
I hope this sounds okay and good luck.