first it depends how old you are, being 42, you are not that young anymore, but you have a while until retirement and have some serious catching up to do so you need to get quite agressive
For starters, you should get in the 401K immediately and at a minimum you should contribute what it takes to get the full company match
a common match is 50 cents on the dollar up to 6% of salary (but this can vary of course by company) - thus if you are making 50K, you will be putting in 3000 and your employer will be putting in 1500
but i would not just be putting in the minimum if you are young, i would recommend setting aside as much as you can afford, 10-15% of salary if you can swing it - time is on your side, the effect of compounding interest cannot be understated and is greatly enhanced by the more you put in and the longer you have it invested
you should not be afraid of the stock market in general if you are young regardless of what all the doomsayers are saying these days - the market will rebound, and you cant time it so, just get in and stay in, dollar cost averaging into the market every month
i would select a combination of growth, growth and income, international, mid cap, type funds, maybe some bond funds - also be wary of having too much invested in your company's stock
as far as individual stocks, invest in companies that pay a dividend and have a history of increasing that dividend every year - look into oil, utilities, consumer discretionary - generally whoever the leaders of a particular industry are - you mentioned Walgreens, i would consider them a leader in their industry, but do some basic research