The ladies over at titus2talk have compiled a list of their readers favourite biographies. No doubt it’s not exhaustive but there are some great books listed there, I can vouch for a few of them.
Biographies are a useful tool for learning much through the experience of others and the very style of many of them make them easier reading for periods when you have less time or no concentration span to read. I always found when I am struggling in life for example in the post-natal periods it is not advisable to be wrestling with the theologians books, but much wiser to allow God to teach you to rely on Him by showing you others experiences.
The Bible is full of biographies, it’s good to also read how others (who lived not just so long ago) used Biblical principles in their lives to overcome their struggles.
If you’re at a low ebb with your reading or if you just need a change head on over to titus2talk and check out their list.