newbie with chain questions

hi all. any one care to help a newbie? so after a bit of a winter slumber i took my mtb out today for the first time this year. i only took it on the paved path by my house. just before climbing a hill i had some problems with shifting the back gears while in the small chain ring. i made sure i wasn't making the chain like \. it felt like it wouldn't change gears... kept making noise but not moving. sorry for my non-technical explanation. i just cleaned and lubed it yesterday. my bf suggested chain stretch but i haven't put that many miles on it. is this something i can fix or should i just take it in to the lbs tomorrow. shifting in the middle or large chain ring were fine. any help would be great as i'd love to get more riding in tomorrow and sunday. thanks a bunch!
-m

It's possible your shifters are gunked up. It happened on my bike, the guy at the bike shop fixed it up for me.

It might be your derailleur too. Try loosening one of the screws (the outer screw limits the outward movement of the derailleur, and hence the chain, and vice versa. The looser the screw, the more sideways movement the chain has).

Turn the bike upside down and try shifting through all the rear cogs on each of the different front sprockets. Then tell us which gears it doesn't reach. If it goes to every rear cogs on the outer chainrings but not the inner one, that would be rather odd. If it simply doesn't reach the inner rear cog on any chainring, then either you need to take slack out of the cable (it has stretched) or adjust the inner stop screw on your rear derailleur. To take out cable slack, shift the derailleur to the outermost rear cog, loosen the allen screw on the rear derailleur which holds the cable, stretch it with pliars, and retighten the screw.

Thanks for all your suggestions!

Deb, I did what you said and it does skip the larger cogs no matter what chain ring I'm in. I tried pulling the cable tighter like you said, I also referred to my bike maintenance book and it said to turn the cable adjuster on the rear derailler. Tried both and still kept skipping. So, off to the lbs it went. I should get it back tomorrow. It's thunderstorming today so I'm not missing any good riding. Hopefully I'll get it back tomorrow.

Thanks again! :)
-m