From White Rose Maths – new digital tools are free for use by teachers and parents. You can watch the short webinars introducing their first two new interactive tools – Place Value Charts & Algebra Tiles – scroll down to the Resources and CPD collection. This is an outstanding resource and very easy to use.
An excellent read on the subject with examples is one of NCETM’s Using Mathematical Representations at KS3 series, Algebra Tiles. NCETM also have a series of videos; scroll down this page.
One of NCETM’s resource recommendations is a very useful Introduction to Algebra Tiles by Ken Wessen on his site, The Mathenæum. It is possible to do the exercises on that site to practice using the tiles.
From the NCTM Illuminations collection – Algebra Tiles.
Write x2+6x+11 in the form (x+a)2+b