excavator maintenance?

[thebigo]

Ok, gig is out, this new guy here has some equipment. Thought I should start out a little inexpensive, and I know because of that, probably got some cheapness within. I didn't want to build cause I don't have the time. Would like to post some pictures, but not yet computer savvy enough to do so. Anyway I am really happy with my purchase, as soon as I find out how to post pictures I will do so. Got a RC4WD excavator and there 8x8 armageddon dump truck., have about 6 hrs each on them after tweaking.
Since this equipment came with very little directions for use and maintenance, was wondering If any body could help with some questions on the excavator?;
1. what type and weight of hydraulic oil can I use, (outside of RC4WD oil) and how often should I change It?
2. Saw a couple posts that Joe (LILGIANTS) replied to, about a filter and pressure gauge.
a. Hydraulic filter? not sure if I have one already installed or not? If not should I install one?
b. pressure gauge, where can I get one? Is this just a local hardware store
item?
3. should I grease any of the fittings or bushings, after each use, or several uses?

any help would be much appreciated, Thanks David