The IFS TaxLab has loads of resources that might be helpful.
The Key Questions section currently has 10 articles on interesting topics within tax. The articles are very nicely structured with clear subtitles, so even weaker students could have a go at making notes to summarise them.
The Where do you fit in? section includes a handy tool to show where different levels of income fit within the UK distribution. To help your students to see why such an understanding is important, you might want to show them this classic clip from Question Time where an IT analyst appears to think a salary £80k/year is in the bottom half of the distribution.
The Video Explainers are also nice and clear.