Instead of me going over complelety old ground that has been covered elsewere (
http://www.entropiaforum.com is a good site) i will cover only the main salient points (which have no doubt been covered elsewere again)
When you start of mining, ensure that you carry at least 100 bombs (i often carry 500+) per trip. I have found less than that to be unprofitable.
At the start, use a mining logger (i used to use NRF) so that you can get a feel for what type of ore is in a certain location.
I would recommend that you stick to ore mining only and skill at that, my own opinion only.
Do not buy a tt finder, use a crafted OF-101 (slightly more depth) (can be bought from auction(
Dont tell or ask any1 for mining locations, find them yourself

If you come across some1 else bombing, TP or run out, i feel nothing good can come out of bombing an area that has been bombed 2 mins before.
Best places to bomb if you are low level is places far away and/or were a load of mobs are (preferably in th middle of), however you have to be careful. No point bombing an area that you cant dig up cause of mobs!!!. Good areas for low level are flat lands, especially near rivers.
If you see a good area and its full of 'silly' mobs ie berk, merps etc and ur near water, IF YOU HAVE half decent armour (i have ghost) run straight through bombing, stop for nothing til you get to the water and drown the pile of 20 merps following u. THen you can go back and dig up
Bomb at x2 your search radius, use the P key to track your location (i do this with every bomb i drop), reduce this radious to 1.5 if you get a claim that is at low depth.
Bar the above thats all i can really think of atm thats all i do anyway but i will add to this if/when new thoughts come to me.

If any1 can think of other basic stuff post on here, also dont forget the useful links section