I'm not very pro myself, but ARkon is right, colossi pwns them easy on the standard MMM. As for rushing, the way I like to do it is push for VRs as soon as possible, and wipe out a base structure. THis will slow them down some. But then I'm usually a mid-late gamer.
Here's my strat, has done me some good but apparently not much. Most people playing protoss rush VRs for a reason. They can pwn, and fast. However, they are countered very easily. The aim is to knock out as many core structures as you can and harass the enemy while you are building more VRs. By the time they get countering units, it will (hopefully) be too late. This is a risky strat, and the game is usually decided in the first wave.
A more detailed plan follows.
First, rush probes. This is a risky move, leaves you nearly undefended. Build your pylons in a spread formation, so that they can't kill them quickly and take your defense offline. This depends on whether you are going plan A or B.
Plan A-Quickly get 2 or 3 (depends on how much resources you have) cannons up quickly. I know this is a PvT threat but this works very nicely against zerg, so if you are fighting zerg, you may consider getting 3 cannons. In fact, if fighting zerg drop this strategy and see 'ALTERNATIVE'. This is my usual strategy.
Plan B-Forget everything else I told you. Push out resource gatherers ASAP!!! AT about 6 probes you will want to build a vespene. Build 2 of them stargates, warp in VRs like no tomorrow! (actually you want to build one first, then the second vespene, and build the other). This will leave your base relatively depleted of resources, so if your rush fails, its over. Go in and hit hard at about 5 (or 6) VRs. Don't aim at the units. Hit from the side, hit the main base building. Even if you just take THAT out, you will have crippled your opponent. Though if you lose ALL units you are probably dead.
After your ray's beams are fully charged and BEAUTIFUL, take out the units. This is all about keeping AS MANY void rays alive as possible, while constantly pushing out MOAR. (Hotkeying buildings is your friend). You should have another 6 ready. Retreat your surviving (hopefully 4 or 5) VRs while sending in the new 6. They should meet about halfway, and send em all in together.
VR rush only works if you can quickly charge the laz0rz and shoop da whoop the enemy before they take out your paper thin VRs.
It may seem tempting to let your fully charged VRs continue to pound the base and lose them, as you have a backup wing. Maybe you can pull it off, but I can't. Regrouping is always my best bet, unless they have very very few units left and you can kill them as they train. Much microing is required.
Around after sending in your first 6, you should be upgrading the acceleration so they charge beams faster on your second (and final, if you fail, GG) attempt.
You will now have just short of a dozen VRs going BBBZZZZZ and gawd is it satisfying.
Taunt your enemy (or not) as you raze down all his buildings.
GENERAL POINT: Make sure you hit a building first, preferably unnoticed, every time you have a go. I have seen many n00b protoss players going weapons hot on the tiny bio units. And needless to say, they kill a few, but lose all their precious VRs. Enemy rebuilds faster as their units are cheap, and counterattack. No, you want to charge them up quickly, they don't ALL have to be fully charged before u turn them on the buildings. You can then kill most MMM units in under a second each. Who says VRs arn't good against mass? Sure not as good as colossi, but hell, they dice up anything once fully charged.
ALTERNATIVE
This strategy is untested and purely theoretical, with all the hacks going around I'm not playing ladder. Plus, I got a wc3 map to complete

Based off replays and lots and lots of sleepless nights thinking.
First, get about a dozen probes, and skip the cannons, instead focus on teching for colossi. If you slow down, you're dead. When the first colossi is up it is time to start scouting. If you get attacked early you're dead. However, colossi are great against early game bio blob units. So it should only take you a little longer to get them than the cannons. Risky, but may work for you. Push out 3, get them about halfway. THen as you build MOAR march them and start attempting to lure the bio units out. Rally point should be at the halfway map point. Move back, reinforce, go in for the kill.
Thanks for listening, keep in mind that these strats work great on paper, but may not work so great in combat. Basically if VR rush doesn't work I'm GG'd. Not a pro, never claimed to be. Don't expect to stay in Gold for long. Ain't exactly a 1v1 player, kinda forced into it since I can't seem to find enough of us interested in a 4v4. In fact, when I'm on, hardly any of us ToJ folks are. 3 or 4 if I'm lucky. And I hate games of chance. Some people skip the practice matches and get us all instapwnt.