I second TEs or teachers Tv easpecially the great lesson ideas section. You can also subscribe to the Hamilton Trust and Click teaching for about £30 each, but as I'm a primary teacher I'm not sure if they produce secondary lesson plans. Buying ready made displays on e-bay that you just have to print is also really well worth it.
Creating all his lessons from scratch is pretty impossible especially as he would have better lessons if he adapted what has already been made from others. He needs to prioritise what will directly impact on the children's learning, a perfect worksheet is still only a worksheet but an inspiring whiteboard start on his interactive whiteboard, there are lots of these on teachers tv would be more likely to help children with there learning. I know I'm being bossy, Saturday night wine but rather than producing fantastic one of lesson, he needs to plan several lesson with an end product/ outcome in mind. For example, in our year 3 class we wanted the child to investigate and record data about the classes favourite crisps, day one tally charts. day two frequency tables, day 3/4 bar charts. I expect he can think of a similar task for secondary. The final product was all that needed marking, the children were doing lots of group work, speaking and listening, very motivated and it planned itself.It is essential that children problem solve and speak about maths which means he marks less and bases his planning on what they find hard. Hope I didn't waffle