My best advice is don't get caught up on features. Most sewing machines on the market simply advertise based on how many functions it can do. For example, I was channel surfing just a few days ago came across a shopping channel segment on a high end sewing machine, which I watched out of curiousity. The whole sales pitch was basically "Look at how much stuff it does!" Most of it's "cool features" would only be used every once in a blue moon by even a proflic sewer, and many of those are just "lazy" versions of things than can be done with a more basic sewing machine or by hand (which sometimes, honestly, is better).
Excuse the rant. tl;dr: bells and whistles do not a good sewing machine make.
What you will always want in a sewing machine is good, solid construction and a good motor. Unfortunately, this isn't something that's as readily advertised as the bells and whistles. If you can get to a store where they let you test run a machine, that's ideal--bring scraps of denim (old jeans are great) or canvas or anything tough to see what it can do. Even more unfortunately, many chain stores don't let you demo a machine like that. In that case, your best bet is to ask around. Ask anybody you meet in the store what sort of machine they use, and what they use it for--in this case, the customers opinions may be more valuable than the employees, since they aren't under any pressure to make a sale. Just be polite
As for any my personal recommendations, the sewing machines I've used are a Singer Prelude (borrowed from a friend, don't recall the model #), a Kenmore that's probably as old as me (borrowed from Mother), Janome 2212, and Bernina Bernette 65 (just looked at the Bernina website, and it appears to be discontinued, I think it's comparable to Bernette 66)
Out of those my favorite was the Bernette, and the least favorite was the Singer Prelude. The Kenmore might have been very nice after some TLC, but it was on its last legs by the time it got to me. For entry level, I think the Janome 2212 might be good--it was the first sewing machine I owned myself, and I still sometimes use it. I think mine cost somewhere around $150 dollars, if price matters.
hope this helps