Planting Plants

I all so I've taken the plunge and decided to keep fish, I'm going down the live plant route they look so much better.. My question and sorry if it's a daft question but I'd rather be embarrassed but got it right then stay silent and make a hash of things. The plants do they go into the gravel in their pots still or are they treated just the same as house plants and removed from pots and into the gravel. Cheers.

Thanks for you help Colin much appreciated.

Ta Colin, I wish I'd asked this question when I first started planting up my tank, I lost a few because I planted them too deeply. A most useful article.