Putting up floating shelves

Floating shelves usually come as a pack with a shelf outer and a metal dual pin type bracket ( and screw fittings ). You will need a hammer drill, rawl plugs if it's a brick wall, possibly a size 6 masonry drill bit , a spirit level and a hammer to knock in the rawl plugs. Mark the metal bracket where you want the shelf to go make sure it's level, mark the holes drill and fix the bracket using the screws that are usually provided. Then slip on the shelf outer, secure that with the grub screws that usually come in the pack and you're done !

Same as Mark, just dont stick heavy stuff on them

Make sure there is no sockets above or below the shelf. Wires should run vertically or horizontally to a socket or switch. Also check for any pipes i.e radiators. Use the correct wall plug for the wall material ( brick wall plug, plaster board spring toggle or similar) they really are quite simple to do.

As Mark Gates and if you are drilling tiles stick masking tape across the tiles, mark the tape and drill carefully and slowly to start off with. Good luck !