Please refer to the RSPB website as your main reference.
This guide is specific to the design of the Bodging for Birds idea and it is up to you to provide suitable safety for installers and find suitable sites.
As supplied the nest boxes have a 25mm entrance hole that is suitable for blue, coal and marsh tits, but there are steps in that entrance to guide a forstner drill bit so you can modify them easily to
28 mm for great tits, tree sparrows and pied flycatchers, 32 mm for house sparrows and nuthatches, 45 mm for starlings.
With a jigsaw you could also modify them into open front nest boxes, e.g. Box with 100 mm high open front may attract robins or pied wagtails. A wren would need a 140 mm high front panel, while spotted flycatchers prefer a low 60 mm front to the box. Please use the RSPB guides for suitable locations for different bird types.
The lid of the box should be secured with a single screw, this is to prevent predators from knocking off the lid, while allowing the lid to be removed for future cleaning / maintenance. As supplied the box may be full of wood shavings, this is just to aid the drying process of the timber and should be emptied before installing.
The nest box should have a short plank screwed to the back of it which can in turn be screwed to the tree or structure that it is installed in. Rust proof screws should be used for obvious reasons, and as you will probably be standing on a ladder it makes sense to drill small holes and fit the screws to the backing board on the ground, reducing the number of hands needed once up the ladder.
There is space below the entrance for you to add a tracking number, or logo. Please only use water-based paint for this, wild birds are far more sensible than humans, any chemicals will prevent them from using the nesting box.
Follow up inspections, obviously you will want to know if the nesting boxes get used, if there is no sign of occupation over a year or two, perhaps you need to rethink the location or entrance modification.
Deterioration, this is untreated timber and will decay over time, it will be years before it becomes unusable, however Autumn inspections are advised. Any splits in the wood can be filled with natural fillers e.g. moss or clay and grass fibres mixed into a filling paste. Please avoid plastics and chemical fillers! After a few years the nest boxes should have the lid removed and be cleaned out, this is a good time to make repairs or replace if needed, but follow RSPB advice on timing and ensuring that the nest box is unused at the time of maintenance.