weight training.

What timing, I just logged on. Depending on what size weights there is all kinds of stuff you can do. I'm no real expert, but it stands to reason that unless you lift hard and heavy you aren't going to put on much mass. The weights you are talking about will make the muscles more useful, and will keep them from Atrophy, but they aren't going to get real big. One thing that I have found that gives one heck of a burn is a moderate weight with a real slow return. Ex. the bench press: push up at what ever speed you want, but as you bring it back to your chest count to 4 before you are all the way down. Keep it moving the whole time, just make it take 4 seconds to bottom out.

The way I go about it, I reiterate not being an expert, is 1 large group and 1 sub per day. So monday is chest (large) and then Bicep's(small). So I aim for 3 exercises of each. Today's workout as another example:

flat bench press, 4 sets, 10-12 reps
incline bench press, 4 sets, 10-12 reps
dumb bell fly's, 4 sets, 10-12 reps
Incline alternating bicep curls, 3 sets, 8-10 reps
bar bell curl, 3 sets, 8-10 reps
preacher curl (or an isolation since you probably don't have the equipment), 3 sets, 8-10 reps.

tuesday is legs and ab's, it would be easier if you could get some bands for home use on some of these.
Squats,
leg extensions
leg curls
calf raises

thrusday is shoulders and more ab's.
Front raise
lateral raise
Bent reverse fly
Trap raise
and shrugs

Friday is back and tri
back is difficult to do at home except for rows. There are some good ones on line.
Tri's
modified dips using the side of your bed
Skull crushers
1 arm tri extensions
I also like to add a 2 arm tri extension behind the head while seated (don't remember the name).

These are the ones I do at home if I am unable to get to the gym. Just remember to go slow and it will burn.

When I am on schedule with my training, I will do two days a week of strength training. I like to focus primarily on upper body and core since I feel my running takes care of my legs. Plus, the focus on the upper body gives my legs a little rest. I have been doing the p90x workouts for chest/back and shoulders/arms (I usually do a little of the abRipper at the end of each workout, too.)