Tips for motorhoming in Ireland

(Moved from Touring Cheaper

My husband and I (both in our 70's) are fairly new to motorhome holidaying. We hope to travel to Ireland for 3 weeks in June/July and would welcome any tips on:

1) ferries

2) 'CL' type sites (particularly in Southern Ireland)

3) do we need different plugs for our electric hookup? 

4) or in fact any tips which might be helpful in holidaying there over a 3 week period - anything I should be aware of that I might not!

Thanks in advance, Susan

(Hope this is the right place for this post)