Look on the "screwfix" site Dawn. For home use 14.4 volt is ample, with 13mm keyless chuck. get either a De Walt, Makita, or a "blue" bosch (not the green). At around £100 - £140 any of them will be fine. A drill driver is the most useful overall, it does what it says on the box, :-) Can drill, or with a screwdriver bit, drive screws home, has the benefit of not being as heavy as a combination drill, which has "hammer" action as well, for use with masonary bits and drilling into walls etc. A mains operated hammer/percussion or sds drill is the best when you're going into brickwork/masonary, battery operated drills make quite hard work of it unless the material is relatively soft. The combo drills are uncomfortable to use for any length of time for normal drilling/screwdriving due to the heavier weight, I much prefer to use a drilldriver. Be warned that cheaper makes of drill can be rubbish. Even though they may be 18volt say, they have no "oomph", no torque. The makes I suggested will have. My own Bosch has 50nm of torque, ample. You might look that figure up if it's available for the drills you look at.