Worksheets are often seen as the epitome of 'lazy' teaching and nearly all teachers I know use themvery rarely nowadays. But the fact is that sometimes the old worksheet is is a great learning tool and worksheetworks.com has an absolute 'sheet load' of worksheets that you can generate to meet the specific needs of your students.
English, Maths and puzzles are the core content of worksheetworks.com but there are plenty of options to make a worksheet to meet your needs due to the ever increasing library of content on the site.
All in all - worksheetworks.com should be in the back of every teachers memory next time you need a work sheet as this allows for far more personalised learning opportunities than simply photocopying a generic sheet from a resource book.
Oh of course it is all free too. Check it out here.