I would say that there are materials for all the levels, but most of them fall within the Básico (elementary) and Intermediate scale.
Janis has devised a very basic choice of eight general topics (people, work, everyday activities, home, community, our world, food, health), which later on are divided in subtopics. For example, in the general topic of people you can find the following subtopics: clothes, culture, dating, appearance, personality, family, feelings, friends, heroes, immigration, marriage, small talk, superstitions.
If you click on any of the subtopics, you find a menu which includes activities to practise the four skills, grammar, vocabulary and further links to explore the topic.
Janis's ESL Home Page may take a while to get to know in depth, but the wealth of materials shouldn't be dismissed at all either by teachers and students alike.
