When choosing resources for students there are a number of factors to consider:

Does the resource cover the current course content?

Online, there are many resources available. However, some of these are really useful and do a good job of covering the course content, others do not. When choosing resources they should be exam board specific and based on the UK curriculim. Students have a specific list of content to learn and it is important that they focus on this material and not on material which will not be examined. 

Is the resource of the correct ability level of the student?

In the UK there are two main ability levels considered foundation and higher tier. Students will sit an exam for either foundation or higher. The foundation paper is more simplistic with word blanks, multiple choice and some short answer questions. The higher tier is mostly short and longer answer questions. So, when choosing resources it is important to target the resource onto the correct ability level for the student. 

Will the resource allow the student to make progress within the subject?

A student will only be able to make progress if they can fully access the resource. Also, they will need to be able to review their answers against a mark scheme to see where corrections need to be made. If the resource targets the course content well and is of the correct ability level and the student is able to check their answers then the resource should be able to help them make progress within the subject.