I recently had a little one and knew nothing about this side of things. There is luckily a website for dads that has this and a lot more information readily available with links to government info too. I dint know about long term illness but almost everything else is means tested so it depends on your Partner s wage.Try the website below for links in the about money section.
www.entitledto.co.ukput in details and they will tell you everything you can get.