El had a PEG at 3 so all the luer lock syringes will fit. we have a gastrostomy nurse who saw him first to fill us in with what you do in general terms. She works in tandem with the dietician and liases with school and us. Not sure how individual LAs work tbh.
We have an emergency kit given and instructions on how to pop a catheter into the hole should the PEG come out. If the hole closes. which it does fairly rapidly, its another op to reinsert. The gastrostomy nurse is the one with all this stuff and info. We were given a pump by the hospital who did the PEG.
The hideous dangly tube we always secured with a piece of mepore tape to stop accidental pulling, it also tucks into the waistbands of trousers and skirts. You can always cut it a bit shorter but not so much as it is too short! It stayed clean and uninfected for about a year before getting gunky and infected. We use buddy buttons as they are brilliant for keeping the area clean and minimising infections. Most infections can be cleared up with some stuff the nurse gives you (anti inflammatory) and chloremphenicol eye ointment over the counter and we rarely resort to systemic antibiotics.
The nurse should tell you about rotating it recularly to stop it embedding. Also some (?) silver nitrate to stop overgrowth. All sounds scary but its easy once you get going.
You can buy belts to cover the peg and protect it from rubbing on clothes. You can also get a lycra tube which does the job very cheaply and on prescription. Sorry dont know the name of it. You can get gastrostomy vests from rackety which have a tube opening but a bit expensive. Easier to cut out a section of a normal vest, but it all depends on how active the child is.
In hospital its quite uncomfortable for a bit so make sure your DD is topped up with regular calpol. Take in favourite books and a portable DVD player. They keep the PEG 'dry' for a bit and slowly give water and then formula via a pump. Once it is all tolerated you go home 
El never tolerated formula well so we blend food and put it down the tube, initially the PEG, but now his mik key button. But thats a whole different story 