Business valuation - Please Help

I am currently doing work experience for an investment bank and will be given a task to value a business using either Discounted Cash flow (DCF models) or transaction comps.

I understand the basic principles of working out cash flow and then applying the interest rate to get discounted years but I don't fully understand it to the full extent and am still unaware how to calculate terminal value.

Any help/ links to guides will be greatly appreciated.

Thanks in advance