There is a create> Object or something like that in the menu up the top.
Im saying this from memory, so it may not be accurate.
Anyway, u can create spheres and cylanders there...play around with the values it asks you for to get something that is right size, but what i usualy do is create a cylander of any size, use the scale(icon on bar at top, next to rotate(use values such as 1.4 to make it bigger, 0.5 to make it smaller, but it doesnt need huge values!) to get it to the width i want, then select one of the ends, press x or y buttons to lock the corresponding axis, (so it only moves one way, thus not going out of line) and drag it till its the length i want.
Spheres you'll have 2 play with the values more, but scaling still works
Hope that helps, i cant really explain lods well because im not good at them myself