well, the target will mostly be pollack, mackeral and wrasse.
for the wrasse, just use a normal single hook rig, i like to use a 3 way swivel or a loop, attach a short 8-9 inch snood then the hook, then have about 2 feet of line to the lead. this keeps the hook close enough to the bottom but hopefully away from snags. be prepared to lose tackle. its inevitable. as for bait, rag and small hardback crabs would be best, but mackeral will do. limpets are also quite good.
mackeral, sure you know yourself, a string of feathers does just fine.
for the pollack, you can either spin, float fish or freeline. spinning, i would thread a ball lead(about 2oz) down the line, then a bead, tie on a swivel, then have about 3 feet of line to a plain hook to which you could add a jellyworm, or even just a strip of mackeral. the storm shads are also excellent. float fishing is simple, just a sliding float and a strip of mackeral, bear in mind that some places are quite deep. my personal choice is freelining, partly because you get a great fight, and partly because if you lose your gear, all you are losing is a hook!
bottom fishing is a bit hit and miss out there, and unless you are fishing off a beach be prepared to lose lots of gear. however, i did do a bit last time i went and got dogs and a conger. i cant really tell you what to expect though, anything could turn up! standard 1-2 hook rigs baited with mack should do the job though.
as for the marks, when me and stevecrow74 fished there we fished the southern end of inishmore. i think the only no-go area of the islands is the Atlantic side, there swells appear with no warning, its very dangerous for even experienced fishermen. then and again this goes for anywhere you decide to fish on the islands, make sure you are not too close(height wise) to the water level, and make sure you have a clear run backwards if you have to. common sense really, but it doesn't hurt to repeat it.
heres the report to the last time i fished there, and if you have any other questions post them up and ill do my best to answer them.
click here for report