Aaah...basil. I love basil. It is one of my favorite herbs. (It could be why I have about 20 starts of it growing right now. I'm a little obsessed.) It is one of the easiest thing to grow, although so many people have trouble with it. There are a few reasons why.
One...it is one of the most cold-sensitive herbs out there. Any chance of frost and it shrivels up the next day into a sad heap of dead plantness. Better wait until end of May or even the beginning of June to leave it out all summer. Definitely still take it outdid during the day...I cart mine outside almost every day for the sunlight; just not overnight. (Because I'm too cheap to buy grow lights...I just pretend they are outside for several weeks to a month.) Its also the reason I start so many...just I case I kill the first round; I have backups.
Another thing about basil...it roots very easily. So easily that it I often have some in a cup of water to use in a day or two; I forget...and bam! I have another basil plant with roots ready to plant. You could really get away with just buying a basil plant at your local nursery, pruning it and just multiplying it from there.
The third thing and probably most important is pruning. So many people just do it WRONG. They either just pull a few leaves off the plant (wrong) or cut it right in the wrong place.
The first thing you want to do with basil is cut it right above the very bottom two leaves.
Can you see where I cut this one? Then what happens is it goes into survival mode and makes two branches of basil instead of one skinny sad basil plant. Then after that you can wait a bit, and harvest EACH branch above those two leaves. (Then you'll have 4; and so on and so on.) you might end up with way too much basil at this point...but just put it in a cup of water (like flowers---NOT the refrigerator--remember, it's cold sensitive?) and you it will even grow roots in a few days and replant or just use later.
If you follow these tips you will have huge bushes of basil, instead of tall skinny lanky ones.