Well, I started back working out after a lazy layoff and decided to get in shape because I feel I'm getting to the age where it's now or never.  The wife and I signed up for a rugged maniac 5k in November to give us a target goal to start.  I am 32, 6'4", 240 lbs.  I am doing the starting strength program for the lifts with a couch to 5k on the off days.
Day 1- lift
Day 2-run
Day 3- lift
Day 4-run
Day5-lift
Day6-run
Day7-rest.. The. Rinse and repeat.  I have already seen gains in my lifts and running but my weight hasn't changed. Before I get slammed, I know that I'm converting to muscle but with this regime will weight loss begin after a period of transition?  I understand diet is probably 90% and I've cut all cokes  and cookies. Main meals are similar to before but smaller portions. I also added in more snacks such as fruit and nuts.

I really would like to lose about 15-20 lbs in the next 3 months which I think I can accomplish.  But at this rate in the gym I feel awesome when I workout but it almost seems I'm leaving a little on the table especially with legs because they are tired from the day before.

My numbers are pretty bad I know but I've never been a big lifter.
Bench max ~235
Dead lift- have t maxed but did a set of 5 @ 305 last workout
Squats- only have access to a smith machine and last set is at 245
Power clean- last set 150
Press-last set at 125

Main question is about my routine and the possibility of over doing it with cardio in between lifts. And also weightloss. Thanks for the help, sorry if this was a confusing mess!

I'm not real familiar with couch to 5k, but doing that with SS *may* be too much. One thing is for sure though, you're not going to get as much out of either program...that's not necessarily a bad thing, just something to be aware of. Not knowing your capabilities or how good your recovery is, I'd start you off with another rest day in the middle of the week- that's what I'd do if I was training you...then I'd re-evaluate after 6 weeks or so.

Dont worry about what a scale says.
Go by what your body tells you.
And whatever ROG says.
Hes basically the smartest man on yhe planet.

That's either quite the vote of confidence or really, really, mean if it's sarcasm

I did couch to 5k to get ready for a run a couple of weeks ago while lifting three days a week.  It ended up being about what you are doing.  I really expetced some good weight loss, but I was very disapointed.

I had better results in weight loss over the winter lifting three days a week, 20 minutes on the bike after my lifts, and either one or two days for cardio.  I was also making steady gains in my lifts at the same time.  Overall I looked and felt better.  I am going back to three days lifting and a dedicated cardio day or possibly two, but not three.

weight loss is all about diet, exercise is about fitness.

250lb people shouldn't run

I agree with the other posters, you should pick what's important to you and do that one first and build a base.   If it was me, I'd do the lifting first and build some strength and work on the diet and lose weight.

but if you enjoy running more, do that, but work on the diet FIRST.

Not sarcasm.

Probably would be a good idea to post your diet and let some of the nutrition gurus critique it for you. I'm not one of them but I do know it is extremely important.