Need some advice on how to increase strength

Split or no split, the key to gaining strength is progressive loading.

I do agree that something like Stronglifts would be very beneficial, though.

More sets, less reps, increase weights will give you strength.

Same sets, more reps(12), increase weights when you do 3(12) will give you more mass.

Also dump the lats pull downs and do pull/chin ups. Bigger bang for you buck.

Make sure your getting enough protein and fats in your diet.

What they said, and are you eating enough?

I am currently eating at a calorie deficit. But I don't want to get any bigger, just stronger. But that might not be a realistic goal.

YMMV, but I can tell you it wasn't realistic for me. At just an 80-calorie deficit, I was losing strength with my workouts, not gaining it. When I switched to an 80-calorie surplus, I started seeing strength gains on all my lifts. For comparison's sake, I'm around 130 pounds and female, and I usually eat 1800-2100 calories depending on whether it's a workout or rest day. Never know, I might still get big and fat from doing this, but it hasn't happened yet.

Do you have a workout partner? If not then maybe that's what you need to get the weight up again especially with bench pressing. Have a look at bodybuilding.com - they've got some excellent tailored workouts on there.

I do work out alone. I work out at school don't want to rely on anyone else to join me. I think I'm the only one of the 10 guys on my class that use the gym at school.

I would ask them anyway, maybe one of them would jump at the chance and is waiting to be asked. You could make their day! In terms of relying on them well they don't have to be there every time. There must be other people in the gym when you are, why not buddy up with someone for the occasional exercise . I go to the gym with my boyfriend, we don't do every exercise together but when I need help pushing out those 'to failure' reps I couldn't ask for anything better. Sometimes he'll just put his finger on the bar, it tricks my mind into thinking he's taken some of the weight and I achieve my goal. Furthermore my buzzing feeling is met with a high five!

Now I'm not one for "programs" but, specifically for bench press, if you are going to commit to increasing this lift, there is a great one out there that I know works: Musclemedia's 7 week bench program. The program claims to add up to 50 pounds to your benchpress within a seven week period, and if you follow it and give it your all, it really can, the friend who convinced me to try did it himself and added over 50, and I added 60lbs once, about 40lbs a second time to my bench going through it, to 425lbs 1RM. Now starting at 115lbs to 150lbs 1RM is too low for +50lbs, thats almost half to 1/3 your max, so be aware your first time through you'll probably go up maybe 30 pounds at most, later you can just do it again. This program is basically just some rules and a bench press chart of what to do when, nothing to buy, no balloney, and once you read and understand the rules you only need the chart and a good spotter. Spotter can be the hardest to find, because you really do need a good spotter, someone who can not only keep you safe doing negative lifts but also knows how to give you just barely enough aid to keep it moving, not some "random gym guy" once your lifts get heavy. Lack of a competent spotter is the main reason I'm not doing it strictly myself again at the moment. Doesn't have to be anyone big, just someone who is attentive, my best spotter was a 120lb girl

Just looked and maybe the site is down? I found another site that has the info directly from the page though, read it and if you work through it, its really worth it, just forget all the other voices, eat about 1g protein/lb of lean body mass/day, dont go in to do the lift without having eaten within an hour or so or tired out after aerobic exercise, read the instructions and follow them and the chart and I bet you'll be very happy with the results, its lots of fun to see this kind of gain in a short time.
http://www.timinvermont.com/fitness/benchpgm.htm

BTW, anyone in the Bellevue/Redmond area looking for a workout spotter/buddy, write me!

The results do vary widely depending on several factors, the biggest of which is where you start, the more you do starting 1RM the bigger the window for improvement is. The chart is set up to do sets, the last 3 sets of 3, 2 then 1 reps of different weight, the last weight is not the max, as you can do a lot more when you havent fatigued yourself with the high sets of 3 and 2 first. Don't get hung up on the time claim either, in my case, I was not even aware of the "7 weeks" claim when I did it, since I got the workout chart from a friend's photocopy, and I did take a few weeks longer than the program says. To me thats not important, what was important is the results.

If you don't have good nutrition, a good spotter, enough sleep, enough rest between workouts, don't complete all the workouts or don't give it your all, you won't have as good of results for each factor. I also took 5-7 days not 3-4 days between workouts as the program says, thats VERY important and what I'd advise too to allow enough time for muscle growth, there are other fine points to work out too for maximum results, but I'm just pointing you to a workout routine which yields great results for people who want to increase bench, I'm not your individual trainer If OP only gets +20lbs doing this program, thats a world of difference to what he's describing. Don't expect +50lbs, thats the "talking point" and name of the routine, you CAN have that much increase, but how much you gain depends on you and your starting point.

A loaf of bread and a $6 jar of peanut butter will make you a whole bunch of high protein sandwiches at around. 400 calories each.

I increased my weight last week.
Now that I started lifting heavier I have developed pain in my elbows whenever I work my triceps, Ex tricep pull down or tricep press. This pain lasts for days. I feel pain when I extend my arms, not flex them.
Anyone ever experience this? Any ideas as to the cause? I'm hoping and praying its not arthritis. I'm due for my yearly physical in a couples weeks, but just wondering if anyone else has experienced this.

I experienced this two weeks ago! I extended my elbow beyond his normal range of motion with too much power. this happend due to a bad form while benchpressing. I worked on my form and didn`t had this problem any more. If you still have the same pain after your workout, maybe you should visit a doctor;it coul be you`re suffirng from a hyperextend elbow.