It's obviously not 100% safe or you wouldn't be asking the question.
Besides what has already been said I'll add based on personal experience and some legal background to not have seeds or grow equipment sent to your house. The UPS guys and the postal people know what's up. Especially packages with amsterdam addresses or grow stores that don't ship discrete. I had a volcano vaporizer in a discrete box sent to my house and the UPS guy knew what it was. All it takes is a two second google search of the companies name and they know what kind of company you're getting things from. Keep in mind delivery people are nosey and they like to talk. Especially if you live in a small town.
I have a funny story about how I got into a bad argument with a manager at an online retailer b/c he changed his mind on me about letting me return something that broke. I was totally pissed and called him a "cocksucker" and then hung up the phone. We had also communicated by email so I quickly realized that he had my email address linked to my account that I had set up with his store. He could have easily found my address because I made the mistake of having the item shipped to my home and all it would have taken was a simple phone call to the police in my town and they would have been on to me.
There was also a recent story about cops watching grow stores and taking down plate numbers and busting people in N. Carolina. I think the grow shop knew it was going on too. Take a friends car, pay cash and make sure you're not followed home. Don't go directly home.
People have already mentioned carbon filters but it goes beyond that. You have to use the CF properly. If you vent directly outside and someone notices a huge, constant amount of air being blown out an opening of your house you will look suspicious. No matter what people will be around your house unless you have a locked gate and a big piece of property. I think it's best to vent into another room and then have a skylight or window open in the adjacent room.
You have to also have to realize that people WILL be in your home unexpectedly even if you own. Plumbers, heating and cooling people, unexpected guests, etc. Every certain amount of years my insurance company needs to do a walk through of my house to renew my home owners insurance. Luckily when they were here a couple of years ago nothing was going on b/c the lady was all over my house with a friggin fine tooth comb looking for reasons to jack up my insurance. She was in every room and the basement. She was here for about 30 minutes and was an a-hole.
The smart thing to do is to never break the law if you don't know what the consequences are. For instance, if you are near a school zone (1000 feet) and they're going to throw the book at you if you get caught then maybe you shouldn't grow.
It's also smart to keep your grows small, 3 or 4 plants, that way it would be considered a personal grow for personal consumption. Don't have any scales, phone lists, or baggies in the house you are growing in. They'll look for reasons to charge you with distribution and at that point it's a whole new ball game.
Keep in mind that if you have a friend over and you give him/her a bud that you've grown and on the way home they get caught and spill the beans and you subsequently get busted you've now distributed. In the eyes of the law even smoking a joint with someone or giving a friend a bud is distribution. It doesn't matter if any money was exchanged.
You should call an attorney anonymously and ask him/her what the consequences would be in your COUNTY if you get caught. That's right COUNTY, because the DA for each county can be either harsh or lenient. Where I live if you got caught with a few plants you'd get two years probation. Two counties over where the DA is harsh you'd get two years in the house of correction.
Don't ever throw any grow materials, packages, leaves, etc, in the trash. They will pick up your trash you put out if they're on to you and look through it. If they find anything related to a grow, anything, they now have probable cause for a warrant.
Be paranoid, be smart, know the consequences and don't think you're smarter than the law. It's their job to catch you.