Well, people have put the J30 into a civic- the question is how much work you want to have to do? If you are looking for a project and you have more time than money, you use whatever you have and take it slow. If you want a project and you want simple, and a lot of power, then you insead drop a B18C into that car because it is the most direct fit with the greatest power.
BUT, if you are just trying to put it back on the road, and this is simply a daily driver needs fixed sort of question, then you but the same exact engine that the car had in it and put that in. Since you say you don't know a thing about cars, I am guessing you are just trying to fix it up- and as such, an engine swap is a big project if you've never done anything on cars before. My advice is get one of those motors from a salvage yard for like $400 and then have someone who has done it before help you so you can learn. In case said "experienced mechanic" is mediocre, I'll save you a couple of headaches and say 1) replace the rear main seal on the engine and front seal on the transmission while you have it apart. There is nothing worse than doing a swap, then a week later realizing the seal is leaking and you have to pull the motor/tranny again to do what you could have done in minutes for $5 before. Then 2) replace the timing belt, water pump, and cam and crank seals. Sane story, it's easier to get to those things while you've already got the engine out. And while you have the engine back in the car but you haven't put the exhaust pipe back up there yet, do the oil pan gasket. All of these tips will same you time, labor, and money later. You will enjoy a trouble free engine if you just do those few things. Also make sure the PCV valve has been replaced, that is also somewhat easier to do with the engine out if the valve is in the can on the back of the block.
You will only need one special tool, the crankshaft pulley removal tool, expect to pay $40 for it, but it is good for all Hondas after you buy it. Take that crank pulley off the old engine and you can get the engine out without having to bring the tranny up too. Then going back in, do the same thing. If you do decide to be involved in the swap let us know and we can give you some tips so you don't repeat little mistakes a lot of people here made their first time around. Oh and welcome to Hondaswap!
