New to dirtbikes

Hello. I am new to dirtbikes and interested in buying one.

Try to include the following info in your first post
1) your physical size - 5'5 125 pounds
2) How physical / aggressive are you ? 6/10
3) what do you plan to ride - neighborhood, lots of fields, woods
4) Do you have any riding experience? ttr90 long ago
5) Do you think you will race ? no
6) Are you mechanically inclined and will you be doing your own bike work? yes
7) Do YOU have a preferance to a brand/ motor choice (2 or 4 stroke)? i want a 4 stoke and i have been looking at honda/kawasaki bikes
8) Do you have a dealer close by your home that you might use and what brand(s) does he carry? yes all dealers
9) How much do you plan to spend on a bike? im on a pretty tight budget
10) anything else that you think would help form an opinion
im not sure whether to go with a full sized bike (CRF150F), a medium sized bike to putt-around on(XR80, XR100), or a little pit bike(KLX110).

What type of bike do you think fits my needs best?

redcat150, i have thought about looking at the chinese bikes but have a bad feeling about them. I would feel more comfortable buying a honda or other big name bike. They are just what ive grown up around. I'm still not sure that a full sized bike would be the best thing for riding around my neighborhood and local fields. I dont need anything more than a playbike. Thanks for the suggestions and anymore would be appriciated.

Thanks for all the suggestions. Now I just have to keep looking in the papers and cycle trader for used bikes in my area for a good price.