at 6 months I started with some fruits like pear, ripe banana, I also gave rusks as he was teething. I gave those in isolation, so a few days apart. Then as he seemed fine with it all, I extended out to other fruits, root vegies and then kept adding things.
Having said that someone mentioned something about dairy and whole wheat bread causing problems, you might want to look into it. But as we haven't had any issues and DD had no issues I haven't been to worried. His tummy and bm's have been OK.
After a little while I just tried lots of things, if he refused to even touch it (like broccoli spears) I just put one on his high chair each meal until he tried it. He did eventually then start eating it. So then I added more foods.
One thing I avoid is cucumber, learnt that one the hard way with Rory, she vomited immediately after she had it 2 times as a toddler. I think the acidity bugs their tummies. That's the only I avoid now.