Below describes the basic principle of floating shelf brackets but specific installation techniques may vary depending on shelf dimensions and other factors.
Required items :

Spirit level
Drill (with 10mm drill bit or 8mm bit depending on the type of concealed bracket - measure brackets and diameters before drilling.)
Spanner (adjustable is best here.)
Tape Measure
Pencil
optional : Sealant for fixing shelf in place.

STEP 1: Identify where you want to locate your shelf.

These shelves are designed to fit in to Stud partitions or into masonry walls. Take care to avoid electrical wires when drilling.

STEP 2: Draw horizontal line where yoo would like the centre of the shelf to be.

We often use the shelf itself draw a level horizontal line and using a spirit level on the top of the shelf, but you can use whatever you want (long spirit level or tape measure). This will act as the centre line of your shelf.

STEP 3: Mark locations for the drill holes / brackets

Measure centre to centre of the pre drilled holes in the shelf (these are normally 700mm centres or 100mm in from each end of the shelf.

Mark the location of the first hole you wish to drill and then measure the distance that you measured from the pre drilled holes in the shelf.

Once you have marked the 2 drill holes for peace of mind hold the shelf up against the holes and check that the marked positions match up roughly with the holes drilled in the shelf.

The concealed brackets allow for some horizontal error (approx 10mm) but attempt to be as accurate as possible.

STEP 4: Drill Holes to necessary depth.

Drill 2 x 80mm deep holes for the brackets. Drill as straight as possible. Again there is room for error but ideally you want these as straight as possible. Some people use a drill guide.

STEP 5: Insert rawl plugs.

Push the rawl plugs fully into the holes until flush.

STEP 6: Screw in the concealed brackets.

The concealed brackets should be screwed in to the neck of the bolt - NOT just the depth of the thread.

STEP 7: Adjust the level of the shelf by rotating the bolts slightly.

Slide the shelf over the brackets - but not the entire way - leave enogh space to adjust the bolt with the spanner. Rotate the bolts individually to get the shelf level. The bolts are designed with eccentric holes (off centre) and this allows adjustment to the height of each bolt. Use a spirit level to check that the shelf is level. Continue to adjust until just right ! Be patient...

STEP 8: Slide the shelf completely over the bolts.

Once you are happy that the shelf is level slide the shelf all the way to the wall. You may optionally wish to add a small amount of wood sealant to secure the shelf in place and around the bolts but this is optional and the shelves will be securely held in place.

STEP 9: Boil the kettle

Sit back and admire your handy work!

If you have any doubt in installing shelves please employ the services of a professional.