Seomra Ranga
Where else can you start. I love Seomra Ranga when I am in Ireland and it is an incredible Irish based Resource site. As an Irish site it is very suitable for the Irish curriculum and no complaints about the Gaeilge which can be problematic on other sites.
It is also FREE!!!
Twinkl
I discovered Twinkl very soon after moving to London. I have a platinum membership and use it so often. I love the resources for display and really like their new resources for the Irish curriculum. Some great info for 1916 and amazing one of lessons perfect for subs!
Instant Displays
If you want your lettering to match your topic then I think instant displays is the perfect site. They also have have displays read to go for different topics and I had their library resources in my class
Fearas Scoile
This is not a resource site but a blog that has links to resources sorted by category.
Phonics Play
Great games for phonics and also has plans to teaching phonics according to Letters and Sounds.
Teaching Packs
Teaching Packs has some brilliant resources for displays or activities and their packs are growing all the time.
Teacher's Pet
Another great website for displays.
TES
Recently TES has allowed teachers to start selling but there are still 1000s of free resources available to download on the site. If you are interested in working in the UK they also advertise jobs on the site