(I am newer at this so I hope my friend Byron will jump in with his advice as he has several stellar planted tanks.)
Starting a planted tank is not as simple as plunking some plants in the average aquarium...
Whether high tech or low tech*, you first need to consider your lighting. You need at lest 1.5 watts per gallon to grow most plants. Most aquariums come with lights that are fine for viewing fish, but not for growing plants. You can go with conventional florescent or newer LED fixtures.
(*High tech uses bright light, CO2, and high(er) ferts. Low tech uses less light, no CO2, and lower ferts.)
Another consideration is the substrate. Sand or fine gravel is best. I'm using silica (pool filter) sand. Others report good success with 'big box' play sand. (either rinsed really well). There are commercial substrates marketed for planted tanks but they are a bit expensive for the real value. Some use sand capped 'dirt' [organic soil], but this is not recommended for the average hobbyist as it presents numerous challenges as the organics are slowly removed. In the case of the latter two, all substrates either begin or will become inert fairly quickly.
The next consideration is fertilization. Since all substrates are, or will become inert (nutrient free), rooted plants will require root tabs to provide necessary nutrients. You will also need to supplement the water column with micro and macro fertilizers.
I'm using Seachem Root Tabs and very modest amounts of Seachem Flourish Comprehensive and Flourish Trace (alternating with Seachem Fresh Trace) - all of these at half or less the recommended dose. Others report success and cost savings using dry ferts marketed for planted tanks.
Note: depending on the bio-load, especially in low tech, you may only need very slight, if any, chemical additives. Fish food and fish/plant waste is excellent ORGANIC fertilizer in the established planted tank.
Then there is your plant selection. There are many to choose from. Aquatic gardening is similar in many ways to gardening in the yard. You want to choose the right plants for the right location. Plants that grow tall are best in the rear while shorter plants are best in the middle and front. Some research is always required. I am having success with Jungle Val, Wisteria, Anubias Nana, Java Fern, Java Moss, Crypt Wendtii, Amazon Sword, Dwarf Sag.
I have had success with those boxed plants with gel from the pet store. However, many of these are grown immersed rather than submerged and often require an adjustment period and sometimes some 'melting'. Be patient.
Since you will likely use more light in a planted tank, algae may be a challenge at first (it almost always is!). This occurs because of an imbalance of light, nutrients and plant load. The best advantage is to initially plant heavy with fast growing plants.
Finally, the best eco-system has a good clean-up crew and tank maintenance. Bottom feeders and snails, especially Malaysian Trumpet Snails are instrumental in converting waste into plant usable nutrients. The MTS also burrow and aerate the substrate which is beneficial for rooted plants.
As far as tank maintenance, I feel you can relax some as the well managed planted tank is not only more natural, but the plants [better] purify the water. You don't have to be as concerned about detritus and mulm on the substrate (I never vacuum the substrate) as this material will decompose to feed the bacteria and the plants. I'm also slightly more relaxed about filter maintenance. Before planting I was pretty regular about cleaning detritus out of filters to remove nitrogenous material. But this material merely breaks down into plant usable nutrients (a good thing).
Water changes: Some would claim that with a planted tank you only top off and don't need water changes. I feel you absolutely still need water changes. However, you may need slightly less frequent or slightly lower volume water changes and still have very pure water for the fish.
I hope this helps some. You won't regret a planted tank as it's amazing how it naturalizes the tank adding a whole new surreal dimension.
To go even a step further, I'm using a Finnex Planted+ 24/7 LED light on my 60g. In 24/7 mode, it comes on at 6am with a red/yellow sunrise, ramps up during the day to bright light (11am-3pm), then ramps down to sunset and moonlight. Way cool.
Good luck!