One important thing would be the material of construction. Usually carbon fibre are the best because they are light and can take a good amount of load. But they can be a little pricey. But if its for indoor use a heavy tripod would be good. Any tripod can be made sturdy just by using the bag provided for it and filling it up with a couple of rocks from around and hanging it from the hook that is provided below the tripod head. Also the manufacturers generally provide the maximum load. Please stick to it because it definitely does matter.
You could find reviews online for recognised brands but not always. But its always better to buy a tripod after looking at it. Not because it wont have the features and stuff but when you just try it out you will know whether you like it or not because tripod like your camera if you take care of it stays with you for ever.
Another piece of advice is that you rather buy a slightly pricey tripod because the construction would be better and all. Also rather than investing on cheaper ones that eventually start giving problems ( eg: Thread of the head breaking off, buckling of the legs etc) and you would have to invest on another one. Rather you buy a good one now and not really worry about changing or anything like that later.