I want to mount a PT 2 x 4 to a cinder block wall in my basement, in
order to build some shelves.

What is the best way to do this ? These shelves may hold a max of 100 lbs.

I have seen those lead "sleeves" which I suppose you screw lag bolts into.
Is that the best method ?

Are there other products which are easier to use ?

I do have some mortor bits, so I am guessing that I can drill into this wall
ok. I don't think it is poured solid at this place in the wall.

Thanks for any tips.

James