I've a basic website with 5 pages. These 5 pages represent a 5 step process. Each step requires data from previous page, which is saved in session. If at any step, required data is missing, page is redirected to home page.
When a crawler crawls home page, it can't go beyond step 1 since required data is missing in next steps.
What should be SEO approach for these kind of pages?
Why do you need the additional steps indexed by a search engine at all?
All of the relevant information that someone could be searching for should be available on the first page anyway, and that's the only one that the search engine is going to index (because there are no HTML links to the additional pages for the crawler to follow).
The information provided on the pages for the next 4 steps, as you say, is tailored specifically to input provided in step 1 and probably shouldn't repeat the information already found on the first page anyway to keep down visual clutter and noise.
Search engines will only ever see the first page unless there is another route to the additional steps that is accessible through html only (JS links do not matter). So you won't be marked down. However, I must ask what it is exactly that you are trying to achieve.
