I just learned about the 70% rule and debt-to-income and some other rules of thumb.All in all, what i'm trying to ask is, are there any important terms and/or concepts that I should really get to know before fully immersing myself into wholesaling?

Not by any means, just takes more experience and creative lead gen to structure favorable transactions with large margins.

Spend your time and not your money when you first start, try not to buy leads. 

And some other good information like last sale, debt level  maturity date etc.

I purchased a lead test kit from Lowes to test for lead-based paint on the exterior of a property. 

The risk in wholesaling is loss of earnest money, spending on marketing that leads to no deals, getting a bad reputation if you put bad deals under contract and have to weasel out of them with unethical escape clauses etc....

I started the Dave Ramsey program and and cleared 150K in debt in a few years. it was at this time that I got into bigger pockets.

@Eric Adobo My debt-to-income ratio is high so it's hard for me to get a mortgage now. 

pay the debt down again.you need to be firm on not to use the HELOC on liabilities, Holidays and cars etc. 

Your all-in cost/debt for those $150-$180k homes should be no more than $105-126k!