Ever thought AIM was full of tiny, highly speculative stocks? Think again. We take a look at AIM's 100 biggest companies, many of which are large enough to be in the FTSE 250 index, should they ever transfer to London's Main Market and get a premium listing. We give our top picks from the AIM 100 in this week's main article in Shares. We also look at how Restaurant Group plans to fix problems in its business; William Cain looks at the specialist lending sector; and we survey three of the most popular investment trust sectors.