I will be installing bamboo stair treads and risers and have some questions:

What is the best way to fasten the stair treads to the stringer? Nails or trim screws? If screws, should I cover with plugs or filler?

Second question is the arrangement of treads and risers. Should the tread sit under the riser above it (tread installed first), or should the riser but against the edge of the tread (riser installed first)?

Thanks.

Glue and finish nails will be sufficient. You can use a finish screw, but you already know the effects.

Work from the bottom to the top.

Riser sits on tread. rip cut the riser board so the cut is under the lip of the tread above.