Junkers is right about local archives. It need not even be your local one, but any where your family came from. Use it as an opportunity to go away and visit the places your ancestors came from, explore the area and visit graveyards and the Archives at the same time. It can prove very rewarding, and sometimes the most unexpected places can provide really exciting and enjoyable breaks. My husband and I, following up both our family trails have thoroughly enjoyed recognised holiday locations which were also family hotspots for us, like the Broads and West Cornwall, but also less obvious holiday destinations like Stockport, Smethwick and Staffordshire. In the Archives you can trawl through Parish Records and other sources as far back as you wish.
Three other useful sources.
One free one is familysearch (IGI as was). They are introducing some great pages of Parish Record images. Norfolk for example is fantastic. Although their coverage is not universal, they are intending to increase it, and unlike Ancestry & Find My Past, you don't have to pay.
Another option is Local Archives online, again for free. The amount varies, but, for example, Norfolk has Wills from 1800-1857, where you can download the image. Warwickshire has criminal records and publicans licences. Also, some have quite cheap booklets - Ayr Archives has little booklets of burials for example.
The third option is Family History Societies. They often provide a search service, they also may provide CDs of records from their area, or even searchable records online. Examples are the amazing CDs from the Birmingham & Midland with all the BDMs (10s of thousands over time) of the main Parish Church in the city, St Martins in the Bullring, and Norfolk FHS which has a great online resource. You have to join the society, but an annual membership may only be the cost of a single Certificate, and you can check online first to see what they offer.