How do you read a burette

lets say if the burette goes from 0 to 50ml top to bottom, is the volume of the solution in the burette 50ml - the number at the meniscus?

Burettes measure from the top since they are used to measure liquids dispensed out the bottom. The difference between starting and final volume is the amount dispensed.

So if the bottom of the meniscus at the end is level with the 50ml mark, it's 50ml that's been emptied from the burette, taking for granted, of course that it started at the 0 ml level.

Yes it is a 50ml burette, the number read at the meniscus is what you have delivered. If you have a 50ml burette that is the maximum measurable amount that burette will deliver.