JoJo

How hard is it to have live plants in your tank

Coryd55

Easy with the proper care.

Read this. It is a very good guide on FL to help you get started in live plants:

General Guide to Low-Light Planted Tanks

Also if you decide to look into it further this website is made solely for aquatic plants:

www.plantgeek.net

Butterfly

Depends on what kind of plants you want If you want low maintenance plants, then you can use low lights, plant and go.
If you want really difficult plants you need high lights and CO2 injection. There are literally hundreds of plants between those parameters. Here is a link for plantgeek.net. figure out what you want then research those plants by needs. start with lighting
http://www.plantgeek.net/plantguide.php
I know your tank is 20G, how many watts of light do you have?
carol

Coryd55

Oh yeah that link is for low light only.

To find your WPG just take how many watts you have in your light(usually on bulb) and divide it by your gallons. So if you have 120 watts of light over a 60 gallon tank. You have 2 watts per gallon. WPG is how plants are divided into high, med, and low light.

Just do what Carol said. Look through the plants and see what you like and then find what you need to get them to grow happily and healthily =)

Cory