Both Mizen Head and Brow Head are on the tip of the Mizen peninsula in the very south west of Cork about 133 km from Cork City. Mizen Head isn't hard to find. You simply keep going until you cant go any further . Heading west out of Cork, stay on N71 all the way west to Schull. From here on out the road become a pretty good regional road out to Goleen.
The road splits in Goleen village with the left turn taking you the long way around via the Crookhaven road and Lisagriffin, whilst the right turn (Barley cove signpost) takes you along the west side of Lisagriffin lake and out to the barley cove hotel and on a few Kilometres further, the Mizen Head Lighthouse Visitor centre.
Mizen head itself, and its lighthouse involves a 5-10 minute walk down steps to a gated bridge. In early morning this is as far as you can go. But seawatching from here can be productive. At 10.30 the visitor's centre opens and for a small fee of 5 euro or so you can enter through to the "Seawatching room" with the permission of the centre staff. I have not visited this room, but I'm told that the Window cannot be opened and even if clean create such an aberration in viewing that it is pointless.
From the gate is your best bet. Or if you prefer you can watch from the car park, but you will be much higher and further back from the birds.
Nearby Brow head should be just a productive, though this is a more open headland and more exposed. The very tip of it is very high and only accessible by hiking over bog and heather. Birders tend to watch from the small cove near crookhaven village, often from the shelter of their vehicles.
I prefer to walk out along the foreshore to the rocky projection to the west of this cove. Its exposed, but the elevation is nice and you are closer to the action. A wind breaker would be a great investment for here.
Both these locations, like most headlands in West Cork, require a good strong Southwesterly wind, with rain or drizzle.
Accommodation is easy enough to find in the area. A number of bed and breakfasts are scattered around the area of Goleen, with the one in Crookhaven being the closest to the birding areas. (45 euro a night is a tad expensive). You will get cheaper further back along the peninsula towards Schull and in Schull itself, though you will have 30 minutes drive in the morning to go birding (making the breakfast portion of your stay moot).
The Barley cove hotel offers rooms and apartments. These can be hard to get in summer season and expensive. But sleep a good number of people breaking down the cost between a good sized group.
The Mizen head visitor centre ha a good café making it very handy for breakfast and lunch if seawatching from Mizen. Crookhaven village itself has a couple of bars and Restaurants. Best of which for food is the Crookhaven inn, which has a very nice menu.
This closes down usually the first week of October however, leaving O Sullivan's bar as the only place for food (Soup, Sandwiches).
Both bars are nice for a relaxing pint if the sun is out, with O Sullivans becoming the Birders haunt in October.
In October an amateur Bird Observatory is run from a rented house in the village (limited numbers for accommodation), but the atmosphere is very good and of course the passerine rarities can be exceptional.
The nearest large town is Schull, with the nearest reasonable petrol station being Ballydehob (important to fill the tank if you want to spend a few days around Mizen). There is a pump in goleen...but its a rip off by comparison.
Schull has a lot of accommodation and bars/restaurants etc...and realistically its not that much of an effort to go back and forth in seawatching season. You just need to be up half an hour earlier. Whether the extra petrol used would balance out with the cheaper accommodation I don't know.
Mizen itself has recorded birds such as Black Browed Albatross, Wilson's Petrel and Fea's Petrel. And with increased observation it would yield more on a regular basis,I have no doubt. Currently it's distance from Cork limits the numbers of birders who visit for this purpose.
However combined with Passerine and wader hunting in September the site holds extraordinary potential as a rarity finding trip for visiting birders, with the gardens on the headland having recorded birds such as American redstart, Yellow Warbler, Red Eyed Vireo, Radde's warbler, Eastern Olivaceous Warbler, Pallas's Warbler etc etc
And Lisagriffin lake and the small beaches around the area having recorded waders such as Pectoral, Buff Breasted, Semi-palmated, Bairds sandpipers, Lesser Yellowlegs, American Golden Plover etc etc.
The only thing that holds Mizen back, is the lack of people going there.