I have uploaded a document from NCTM that really is beneficial for developing understanding of decimal multiplication in your students. If you are a member of NCTM, you can access many great articles to support whatever content you are working on. Making Sense of Decimal Multiplication
Also, one of my favorite lessons related to decimal multiplication is Grid and Percent It from Illuminations. You are combining the understanding of percent and decimal to begin the process of calculating with decimals and percents. This is a lesson that would be a precursor to decimal multiplication. To add to that, I am uploading another activity sheet from mathwire.com that builds understanding of fractions, decimals, and percents through the use of the hundreds grid. You can differentiate the learning by having different groups model different fractions, percents, or decimals and then discuss how they can prove that whatever they were given is also the representation of the other two. So, if I gave one group 1/4, what would that look like on the grid? how could they represent 1/4 to also model the the decimal they would give (.25) and the percent (25%). Or I might challenge another group with something like 1/3 or 33 1/3% and have them justify their answer through the grid. The document you would look for is Fraction-Decimal-Percent Worksheet.
Both documents can be found by clicking on the Content tab within the Learning Math group, then click on Documents.