I have a digital OS map of the whole mainland and use that to plan my rides. If you don't want to buy something like that, there are plenty of websites you can use, some already suggested above.
At the very least, buy
OS Landranger map 103! There are some really great roads shown on that map. I avoid built-up areas where possible, and look for the smallest roads (try to avoid the green and red A-roads, probably the brown B-roads, and search out the yellow roads).
A very obvious ride from Burnley is up to the Kettle Drum at Mereclough, then turn left along the Long Causeway to Blackshaw Head, bear left down to the dip at Jack Bridge, then back up the other side through Colden and on to Slack. From there either bear right to the cafe in Heptonstall (careful on the cobbles!) or carry on left down Draper Lane through Lee Wood to Hebden Bridge.
3 ways back:
- The easy way is to take the A646 back along the valley through Todmorden, right at the mini-roundabout there and back via Cliviger Gorge to Burnley. Depending which part you live in, either stay on the A646 at the junction with the A671 up to the lights at Manchester Road, or turn right down the A671.
- Come back the way you went out, along the Long Causeway.
- Most Scenic (and tiring) way is to turn right along Widdop Road at Slack Top. Continue past Widdop Reservoir, descend with care, then over the cattle grid straight ahead, steepish climb up to the road above, turn left and ride to the crossroads at Haggate, straight ahead and down into Burnley.
I'll come up with some other suggestions when I have time.