There are really only 3 things that commonly cause bricks, and if you protect yourself from them and have an IQ over 20, you should be in the clear.
Bad wads - This is when you install a bad WAD and get a brick from it, usually due to something being off with the banner (Usually custom made channels and stuff). Although this is not really an issue anymore because of WADder, which resizes the image automatically, but you can never be too safe. The obvious precaution against this kind of brick would be to not use custom made channels. That isn't really too fun though, and if you are going to install WAD's, be sure you are protected; either have a modchip or install starfall. This will allow you to auto-boot Twilight Princess and use the Twilight hack to run Wad Manager and remove the bad wad. There are many guides on recovering from banner bricks on this site, so I won't go into this any further.
Brick from an update - These are bricks you can get from installing an update from a game that is a different region from your Wii. To protect against this, either only use games from your region, or run the game through brickblocker or a similar program that can remove updates from games.
Brick from using up disk space - This is probably the silliest way you can get a bricked Wii, but it can happen if you get careless. You can get a brick if you install too many WAD's or other homebrew on your wii and use up all of the disk space. Just be careful and make sure you have enough space before you install all those VC games
These are the most common ways to brick your Wii, and if you are protected against these then you should be fine
Keep in mind, there are other ways to brick your Wii, but they are usually caused by mistakes made under specific circumstances and if you are in one of those circumstances you will probably already know about the risks of whatever you are doing.