Hey there! First off, in terms of RSI I did a whole explanation on it:
https://www.stocktrades.ca/premium/how-to-use-the-rsi-to-make-better-investment-decisions/
In terms of price to sales and price to book ratios, things like that, those get down to the pretty bare basics, so a site like investopedia is going to be great to learn what these ratios are and how best to use them. Ultimately, most of them should be used on an industry level basis. So, comparing the price to sales and the price to earnings of a telecom company to its telecom peers. These ratios will be vastly different from a tech company to a telecom company for example, so they provide little value when used across industries. That's exactly why we have it so you can sort via the sectors.
In terms of the things like CY, NY, SG:CY and SG:NY, those are self explained inside of the screener tutorial. They are simply analyst estimates for this year and next year with earnings and sales. So for example, a company with the following values:
CY: 20%
NY: 30%
SG:CY: 35%
SG:NY: 40%
Is expected to grow revenue by 35% and earnings by 20% in the current fiscal year, and next year is expected to grow revenue by 40% and earnings by 30%.
This is all analyst data. We don't make these estimates.
Does this help? Let me know.