brown plugs are stronger than red. plugs are used in brick or block wals, plasterboard uses a different type.
the plug pack will have marks in it to show the size of drill and screw you need
the hole has to go into the brick, not the plaster, and the screw should be at least 35mm long to get a good purchase. Often shelves and other fittings come with unreasonably short screws.
tap the plug below the surface of the plaster by 1/4" or so. It expands when you put the screw in, and this will reduce the risk of the plaster cracking. You can do this by putting the screw into the plug, tapping the head, then unscrewing it.
Unless you expect to do a lot of DIY, start by buying a light rechargable drill. It will be a bit slower but much lighter, cheaper and easier to use, also handy for high-level work like curtain rails. £25 will probably do. There are some better more powerful ones, but they are big and heavy, which rather defeats the object. If you end up doing a lot of work, you will benefit from having both a small and a big drill. You might find you get a free set of drills with it.
You can buy an assortment of screws. It is quite handy to get zinc-plated ones as they do not leave rust stains when used indoors (self colour steel rusts very easily). Get some with round heads and some countersunk, you will end up needing both. Even when things come with screws, you will sometimes drop, lose or damage them, and sometines they will not be long enough.
You also need a good set of screwdrivers, but the DIY sheds sell very reasonable ones in large packs. Make sure they are made of Chrome Vanadium Steel with hardened tips (the tips are often grey these days). If you buy good screwdrivers individually they work out quite expensive, Don't bother with ratchet drivers with changeable bits.
You can also get things from places like
Screwfix by post or local counter
http://www.screwfix.com/cats/A435572/Hand-Tools/Screwdrivers/Screwdriver-Sets/General-Purpose-Sets
Get a plastic caddy or two to keep your tools and screws in. The sort of thing cleaners use is handy. You can get a posh toolbox later.
p.s. take enormous care to measure and level the places for your holes beforehand and mark the centre with a pencil cross, bigger than the hole will be. If you doubt your ability to hold the drill steady, stick some soft vinyl insulating tape over the place and drill through that (it will prevent the tip skidding)