I have a CHAVRUTA during the week. I prepare on Shabbos. Can i set aside SEFORIM with bookmarks and all materials necessary on Shabbos for this weekday learning? Is it preparing on Shabbos for a weekday?
It is permitted to learn on Shabbos to prepare for a shiur during the week. R’ S. Z. Auerbach zt”l said that the reason is because the person’s neshoma is gaining on Shabbos from the learning, therefore it is considered for the today’s purpose. Regarding placing bookmarks in the seforim so you can remember the proper place after Shabbos, many poskim say that it is permitted. There are number of different reasons offered for this. One reason is because he might want to see that place on Shabbos, ( R’ Y. Belski zt”l, R’ Y. Cahen shlit”a), others say (Orchos Shabbos 22-272) that since it is an small action it isn’t prohibited because of hachana. Another reason brough is since he might forget one of the sources, that would be considered a loss, therefore the placemark is preventing a loss. Others say because the action is noticeable (Shailas Rav 2-28(15).
To sum up, it is permitted.