if you are member you can train on Desert Goats, and for non-member train on Ice Giants or Hill Giants.
a nobermom
Level 3-13 Train on Levels 1-10 Level 14-30 Train on Levels around 20 Level 30-50 Train on Levels 25-60 Level 50-80 Train on 60-100 (Might require food) Level 80+ Train on stuff around your level and train on Greaters when 120+ for fast kills.
Lester demons are good and black demons. the both give good drops.
If you are a member, I suggest you do Slayer tasks, and train on whatever monster the Slayer master assigns. Note that some monsters are best attacked with magic, others with ranged, others with melee, so here you have a chance to train all three combat styles.
Hill giants.
40
Green dragons
Fight cockroach soldiers.
Train it.
monster park is the best place to train only 4 noobs
You can train on hill giants or moss giants.
It depends on what your hitpoints are and what your armour is. However I find the spiders in the third level of the stronghold of security good training as they are aggressive and don't hit terrible high.