Fantastic article about various drywall anchors. Gives weights, drill bit sizes, how to remove - all the things they SHOULD tell you with your new shelf kit, but don't. I'm saving it as a pdf file in my e-reader.
Screwfix HSS Metal Boxed Drill Bit Set Metric 25 Piece Top quality High Speed Steel Jobber Drill Bits. Sizes increase in 0.5mm increments. http://www.MightGet.com/january-2017-13/screwfix-hss-metal-boxed-drill-bit-set-metric-25-piece.asp