Really depends on whose jungling, it's a risk vs reward type scenario... having a jungler can be extremely beneficial. It's important that you have a team balanced around jungling, if people are just going to pick whatever champions they want to play and that's it, then don't be surprised if it doesn't turn out well.
a) Your jungler needs to be aware of the minimap, and help defend a lane when necessary, he also needs to make sure he's ganking whenever possible.
b) the people holding the lanes, need to not push them... last hit only, which forces the other team to push your tower making them much easier to gank
c) you need to have a competent player/champion in the side lane soloing 1v2... ashe, annie, tristana, nidalee, sivir, morgana, soraka, malphite can even do it pretty well with a doran's shield and his passive.
d) when you see the jungler getting ganked or running into enemies on their side of the jungle, middle lane + whichever side lane needs to immediately run to him for support.. i can't tell you how many times i see a jungler die just because his team didn't want to risk dying themselves by helping him out.
don't dodge junglers, you're not helping anybody by doing this... instead, why don't you learn how to jungle yourself on multiple champions so you can help critique the players that are doing it wrong, being nice goes a long way too... don't just be like "omfg jungling noob afk!"