First your baby must be at least 17 weeks old, but it's best to wait until as close to 6 months as is practical.
It's up to you if you want to start with smooth purees, or the baby-led-weaning approach which is to give them normal food, or just mash up your normal food that you're having to a bit more of a mushy consistency. By 4-6 months babies can handle these kinds of textures with no problem, but if they keep pushing the food out of their mouth with their tongue it might be best to stop and try again in a few weeks' time.
If you want to start with smooth purees, you can buy the first weaning jars/pouches, or blend up cooked fruit/vegetables with a bit of baby's normal milk added for smoothness. If you'd like a guide I have heard that Annabel Karmel and Gina Ford both sell weaning guides which are very popular and have nice clear instructions on how much to feed each day etc.
If you want to start with baby led weaning, you should get a high chair or booster seat suitable for babies where the baby can sit in an upright position. It's best if the seat under their bottom is flat so that they have free movement of their arms (there is some school of thought which says things like Bumbo seats change the way their arms move when they are sat in them) - and definitely no recline as this is a choking hazard. When you are eating yourself, sit the baby up with you and offer them pieces of your food/the same food for them to explore. Something about the size of a chip is good because they can pick it up with their whole fist and gum on it.
If you want to start with mashed purees, again choose a high chair or booster seat and bring the baby to the table at mealtimes. Take a selection of the food you're eating, mash it with a fork, remove any bones etc and use a spoon to feed the baby little tastes at first.
I'd say if you're doing puree type weaning (either kind) it's best to start with one meal a day and slowly work up to three. If you're doing BLW then just include them in mealtimes when it seems to make sense and don't worry overly about whether they have one or three meals a day.
You want to give solids in addition to their usual milk at first so keep the milk feeds as normal, but by around 9 months you should have built up to three fairly decent meals per day and so at this point you can begin to drop or stretch out milk feeds. It's also OK to keep milk feeds on demand, as your baby will tell you when they are ready to drop them.
You can also do a mixture of puree weaning and offering finger foods to explore.
For general tips, I found the popover style bibs to easily be the best. Tiny little ones with velcro at the back are too small to be of use and the baby can take them off, anything with sleeves annoyed mine, and the plastic ones with the catching tray also got in the way.
You need to be very careful especially if giving baby normal family/adult food (mashed or not) of salt content. Babies up to 1 year can have a maximum of 1 gram of salt per day so check how much is contained in e.g. 100g of cheese and keep portions small accordingly. If you use a lot of processed foods this might be more difficult to avoid than if you tend to eat things like meat, fish, vegetables, rice. You might want to avoid adding salt when cooking rice, potatoes and pasta, and be careful to look for low-salt stock cubes rather than your usual. Adults can always sprinkle extra salt on their food at the table if you find it bland. Babies should also avoid honey (even cooked) until 1 year old as there is a slight risk of botulism which is very dangerous.
Have fun, and take pictures :)