Need advice on mirror-making for a home-made amateur reflector For example, what would be some good references to read first? What sort of glass slab should I use? What size; diameter and thickness. Im a first-time builder trying to build one
I second the comment about Texereau -- originally written in French; it's the best, bar none. You won't need anything else. 

Remember the old adage that is quicker to make a 4" mirror and then an 8" mirror than it is to make an 8" mirror first. Don't bother with borosilicate. You should be able to get mirror kits and all the abrasives that you need online. Join a club if you can find one.

How to Make a Telescope, 2nd edition by Jean Texereau: 


http://www.willbell.com/tm/tm3.htm
https://www.amazon.com/Telescope-second-Texereau-published-Atlantic/dp/B00EKYQCQS